Core Connections Integrated 2
Core Connections Integrated 2
2nd Edition
Brian Hoey, Judy Kysh, Leslie Dietiker, Tom Sallee
ISBN: 9781603283489
Textbook solutions

All Solutions

Page 371: Questions

Exercise 1
Solution 1
Solution 2
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. We note that the opposite angles of the quadrilateral are equal. Since the alternate interior angles are congruent, we know that the upper and lower line of the quadrilateral are parallel. Likewise, we also obtain that the left and right sides are parallel.

c. Opposite angles of a parallelogram are congruent.

Result
3 of 3
Opposite angles of a parallelogram are congruent.
Step 1
1 of 10
**(a)**

We need to copy the given triangle and its markings and make it a quadrilateral that looks like a parallelogram.

*How can we rotate the triangle to make a quadrilateral that looks like a parallelogram?*

Step 2
2 of 10
As instructed, we can rotate the triangle about the midpoint of any of its three sides to form a quadrilateral that looks like a parallelogram.

Step 3
3 of 10
First, we trace the given triangle. Then, we will pick any of its three sides and locate its midpoint. The midpoint of the chosen side will be point of rotation where we will copy the triangle again. Alternatively, we can trace the rotated triangle by superimposing the corresponding sides which will now be the diagonal of the quadrilateral.

One of the three possible quadrilaterals that we draw is shown below.

$$smalltext{Figure 1. A quadrilateral formed by rotating the triangle.}$$

Step 4
4 of 10
**(b)**

We need to give a convincing argument that the quadrilateral that we drew is a parallelogram using its angles.

*What theorem about angles can we use to prove that the quadrilateral is a parallelogram?*

Step 5
5 of 10
One theorem from geometry that can we use is that if a transversal intersects two lines and the alternate interior angles are congruent, then the lines are parallel. In the quadrilateral that we drew, the two lines represent a pair of opposite sides with the diagonal being the common side of the triangles.
Step 6
6 of 10
With the diagonal as the transversal, the two angles with two tick marks are congruent alternate interior angles so by the theorem above, the left and right sides of the quadrilateral are parallel.

Again, with the diagonal as the transversal, the two angles with two arc marks are congruent alternate interior angles so by the theorem above, the top and bottom sides of the quadrilateral are parallel.

Because the quadrilateral has two pairs of parallel sides, then it is a parallelogram.

Step 7
7 of 10
**(c)**

We need to determine other properties of a parallelogram using the congruent triangles.

*What other parts of the congruent triangles can we use?*

Step 8
8 of 10
We have used two pairs of angles of the congruent triangles and a pair of corresponding sides is the diagonal of the quadrilateral (parallelogram). So, the remaining pair of angles can be used and the lengths of the opposite sides of the quadrilaterals can be used to find other properties of a parallelogram.

Step 9
9 of 10
The sum of the adjacent angles (with two tick marks and two arc marks) are the same on opposite corners. Similarly, the angle pairs with one tick mark are congruent. So, we can conclude that the opposite angles of a parallelogram are congruent.

Because the quadrilateral is formed by rotating a triangle about the midpoint of one of its side, then the opposite sides are congruent. So, we can conclude that the opposites sides of a parallelogram are congruent.

Step 10
10 of 10
**Let’s recall what we did.**

In part (a), we picked a side, determined its midpoint, and rotated the triangle about it to form a quadrilateral. In party (b), we used a theorem about congruent alternate interior angles formed by a transversal intersecting two lines to conclude that the quadrilateral has two pairs of parallel sides. In part (c), we used the remaining corresponding congruent parts of the two congruent triangles to determine other properties of a parallelogram.

Exercise 2
Step 1
1 of 2
a. A parallelogram has two pair of parallel side:

$$
overleftrightarrow{AB}//overleftrightarrow{DC}
$$

$$
overleftrightarrow{AD}//overleftrightarrow{BC}
$$

$$
Downarrow
$$

$$
angle ADBcong angle CBD ( text{alternate interior angles })
$$

$$
angle ABDcong angle CDB ( text{alternate interior angles })
$$

$$
overline{BD}cong overline{DB}(text{ shared side})
$$

$$
Downarrow ASA
$$

$$
triangle ABDcong triangle CDB
$$

b.
$$
Downarrow
$$

$$
overline{AB}cong overline{DC}
$$

$$
overline{AD}cong overline{BC}
$$

Result
2 of 2
Use ASA
Exercise 3
Result
1 of 1
a. He reflected the triangle among the shared side.

b. Kip has made a kite, because adjacent sides of the quadrilateral have equal lengths.

c. The quadrilateral has two congruent angles, but the other angles are not congruent.

d. The diagonal is the line of symmetry of the kite.

Exercise 4
Result
1 of 1
Mathematicians use this process to determine new properties. This is why they first explore to determine possible new properties. Then they write down this possible new property and try to prove that it is correct (without a proof you cannot use it as a property).
Exercise 5
Step 1
1 of 3
a. The diagonals seem to intersect at a right angle.Exercise scan
Step 2
2 of 3
b. The diagonals of a rhombus intersect at a right angle.

c.
$$
overline{FG}cong overline{GH} (text{ Given })
$$

$$
angle FGJcong angle HGJ(text{ Given})
$$

$$
overline{GJ}cong overline{GJ} (text{ Shared side })
$$

$$
Downarrow SAS
$$

$$
triangle FGJcong triangle HGJ
$$

d.
$$
Downarrow
$$

$$
angle FJGcong angle HJG
$$

$$
Downarrow
$$

$$
mangle FJG=m angle HJG=90text{textdegree} (text{ Supplementary angles})
$$

Result
3 of 3
Diagonals of a rhombus are perpendicular
Exercise 6
Step 1
1 of 2
a. The two sides are parallel.

b. If a quadrilateral has two consecutive right angles, then it has at least one pair of parallel sides.

c. Same-sides interior angles are supplementary ($mangle M+mangle P=90text{textdegree}+90text{textdegree}=180text{textdegree}$), thus $overleftrightarrow{MN}//overleftrightarrow{PO}$.

d. No, the right angles could also be opposite each other and then you obtain the form of a kite (which is not a trapezoid).

Result
2 of 2
a. Parallel

b. If a quadrilateral has two consecutive right angles, then it has at least one pair of parallel sides.

c. Same-sides interior angles are supplementary

d. No

Exercise 7
Step 1
1 of 2
Same-sides interior angles are supplementary ($mangle Q+mangle R=90text{textdegree}+90text{textdegree}=180text{textdegree}$), thus $overleftrightarrow{QT}//overleftrightarrow{RS}$.

Same-sides interior angles are supplementary ($mangle Q+mangle T=90text{textdegree}+90text{textdegree}=180text{textdegree}$), thus $overleftrightarrow{QR}//overleftrightarrow{ST}$.

Thus the rectangle has two pair of parallel sides and thus the rectangle is also a parallelogram.

Result
2 of 2
Rectangle has two pairs of parallel sides
Exercise 8
Step 1
1 of 1
Rectangles are also parallelograms.

If a quadrilateral has two consecutive right angles, then the quadrilateral is a right trapezoid.

The diagonals of a kite intersect at a right angle.

A parallelogram has two pair of parallel sides.

Exercise 9
Step 1
1 of 2
$$
overline{AD}cong overline{BC} ( text{given })
$$

$$
angle ABDcong angle CDB ( text{alternate interior angles })
$$

$$
overline{BD}cong overline{DB}(text{ shared side})
$$

$$
Downarrow SAS
$$

$$
triangle ABDcong triangle CDB
$$

Corresponding sides of congruent triangles are equally long:

$$
6x+6=8x+2
$$

Subtract $8x$ from both sides of the equation:

$$
-2x+6=2
$$

Subtract 6 from both sides of the equation:

$$
-2x=-4
$$

Divide both sides of the equation by $-2$:

$$
x=2
$$

Result
2 of 2
$$
x=2
$$
Exercise 10
Step 1
1 of 5
In this exercise, we need to use the given diagram and information to prove that the two pairs of segments are congruent.

*What properties of parallelograms might be useful in our proof?*

Step 2
2 of 5
It is given that the shape in the diagram is a **parallelogram**, which is a quadrilateral with two pairs of opposite parallel sides. Parallelograms have the following properties:
* Opposite sides of a parallelogram are congruent.
* Opposite angles of a parallelogram are congruent.

The diagonals of the parallelogram divide it into triangles so the following triangle congruence theorems may also prove useful:

* **SAS:** If two triangles have two pairs of congruent sides and the included angles are also congruent, then the triangles are congruent.
* **SSS:** If two triangles have three pairs of congruent sides, then the triangles are congruent.
* **ASA:** If two triangles have two pairs of congruent angles and the included sides are also congruent, then the triangles are congruent.
* **AAS:** If two triangles have two pairs of congruent angles and a pair of non-included sides are also congruent, then the triangles are congruent.

Step 3
3 of 5
**Plan:**

Before we start the proof, let’s make a plan on how to go from our Given statement to our Prove statement.

Since we are trying to prove that segments are congruent, let’s use the congruent opposite sides parallelogram property to label all the pairs of sides we know must be congruent. Also, label the congruent angles. Recall that vertical angles are congruent and alternate interior angles created by parallel lines must also be congruent.

Note that we can label our diagram in two different ways, depending on what pair of triangles we want to use in our proof:

$$text{Figure 1: }triangle WXMtext{ and }triangle YMZ$$

$$text{Figure 2: }triangle WZMtext{ and }triangle YXZ$$

Notice for both Figure $1$ and Figure $2$ that we have all three pairs of congruent angles and a pair of congruent sides so we can use either AAS or ASA to prove the triangles are congruent. However, in the given flowchart, only one oval can be for congruent alternate interior angles so we will need to specifically use AAS to fill in the given flowchart proof.

We can choose to use either figure for our proof.

Our plan for both versions of the proof is:
1. State our given.
2. Use the definition of a parallelogram to state a pair of lines are parallel.
3. Use the Alternate Interior Angles Theorem to prove a pair of angles are congruent.
4. Use the Vertical Angles Theorem to prove a second pair of angles are congruent.
5. Use the congruent opposite sides of a parallelogram property to prove a pair of sides are congruent.
6. State a pair of triangles are congruent using AAS.
7. Conclude the two pairs of sides are congruent since they are congruent parts of congruent triangles.

Step 4
4 of 5
The proofs for both figures are shown below.

**Proof for Figure $boldsymbol{1}$:**

**Proof for Figure $boldsymbol{2}$:**

Step 5
5 of 5
**Summary:**

First, we recalled some of the basic properties of parallelograms and the triangle congruence theorems. Then we decided which of these was useful for our proof. After applying the appropriate properties to our diagram, we made a plan on how to go from the Given statement to the Prove statement. Using our plan, we then constructed a two-column proof.

Exercise 11
Step 1
1 of 2
The number that is exactly half way si the sum of the two numbers, divided by 2.

a.
$$
dfrac{9+15}{2}=dfrac{24}{2}=12
$$

b.
$$
dfrac{27+3}{2}=dfrac{30}{2}=15
$$

c.
$$
dfrac{10+21}{2}=dfrac{31}{2}=15.5
$$

Result
2 of 2
a. 12
b. 15
c. 15.5
Exercise 12
Step 1
1 of 2
a. Irrational, because $sqrt{5}$ cannot be simplified.

b. Rational, because the expression contains only fractions and no roots or other irrational numbers.

c. Irrational, because $sqrt{11}$ cannot be simplified.

d. Irrational, because $sqrt[3]{9}$ cannot be simplified.

Result
2 of 2
a. Irrational
b. Rational
c. Irrational
d. Irrational
Exercise 13
Step 1
1 of 2
We note that the first figure is a square with side 3 minus one block (when rearranging some blocks), the second figure is a square with side 4 minus one block and the first figure is a square with side 5 minus one block. Thus we then obtain the equation:

$$
f(x)=(x+2)^2-1
$$

Result
2 of 2
$$
f(x)=(x+2)^2-1
$$
Exercise 14
Step 1
1 of 3
a. We note that there are 12 possibilities.Exercise scan
Step 2
2 of 3
b. We note in the tree diagram that there are two branches that contain a high-fiber snack out of the 12 branches:

$$
P(high-fiber)=dfrac{2}{12}=dfrac{1}{6}approx 0.167=16.7%
$$

Result
3 of 3
a. 12 possibilities

b. $frac{1}{6}approx 0.167=16.7%$

Exercise 15
Step 1
1 of 3
Determine all lengths in the diagram using the Pythagorean theorem:Exercise scan
Step 2
2 of 3
The area of a triangle is the product of the base and the height divided by 2. The area of a rectangle is the product of the length and the width:

$$
AREA=dfrac{3cdot 6}{2}+9cdot 5-dfrac{3cdot 3}{2}-dfrac{6cdot 3}{2}=45-4.5=40.5
$$

The perimeter is the sum of all lengths of the sides:

$$
PERIMETER=5+3sqrt{5}+3+2+3sqrt{5}+3sqrt{2}=10+6sqrt{5}+3sqrt{2}
$$

Result
3 of 3
Area 40.5

Perimeter $10+6sqrt{5}+3sqrt{2}$

Exercise 16
Step 1
1 of 3
a. Congruent, because of SAS. Determine $x$ using the Pythagorean theorem and that corresponding sides of congruent triangles are congruent:

$$
x=sqrt{10^2-8^2}=sqrt{36}=6
$$

b. Congruent, because of ASA. Corresponding sides of congruent triangles are congruent:

$$
x=BC=AD=10
$$

Step 2
2 of 3
c. Congruent, because of AAS. Corresponding sides of congruent triangles are congruent and the tangent ratio is the opposite side divided by the adjacent rectangular side:

$$
tan{35text{textdegree}}=dfrac{11}{x}
$$

Multiply both sides by $x$:

$$
xtan{35text{textdegree}}=11
$$

Divide both sides of the equation by $tan{35text{textdegree}}$:

$$
x=dfrac{11}{tan{35text{textdegree}}}approx 15.7
$$

d. Cannot be determined, because we don’t know whether the two triangles are congruent (as the angles of the triangles are the same but the sides do not necessarily have the same lengths).
Result
3 of 3
a. $x=6$

b. $x=10$

c. $x=15.7$

d. Cannot be determined

Exercise 17
Step 1
1 of 2
$$
angle ADB cong angle CBD (text{Given})
$$

$$
overline{BD} cong overline{DB} (text{Same side})
$$

$$
angle ABDcong angle CDB (text{alternate interior angles})
$$

$$
Downarrow ASA
$$

$$
triangle ABD cong triangle CDB
$$

$$
Downarrow
$$

$$
overline{AD} cong overline{CB}
$$

Result
2 of 2
Use $ASA$
Exercise 18
Step 1
1 of 3
a. Factor out the greatest common factor:

$$
15x^2+39x-18=3(5x^2+13x-6)
$$

Factor further:

$$
15x^2+39x-18=3(5x-2)(x+3)
$$

b. Factor out the greatest common factor:

$$
6t^2-26t+8=2(3t^2-13t+4)
$$

Factor further:

$$
6t^2-26t+8=2(3t-1)(t+4)
$$

Step 2
2 of 3
c. Factor out the greatest common factor:

$$
6x^2-24=6(x^2-4)
$$

Factor further using difference of squares:

$$
6x^2-24=6(x-2)(x+2)
$$

Result
3 of 3
a. $3(5x-2)(x+3)$

b. $2(3t-1)(t+4)$

c. $6(x-2)(x+2)$

Exercise 19
Step 1
1 of 2
In a 30$text{textdegree}$-60$text{textdegree}$-90$text{textdegree}$ triangle, we know that the shortest leg is half the hypotenuse. The length of the longest leg is the length of the shortest leg multiplied by $sqrt{3}$:

$$
x=6sqrt{3}
$$

$$
y=2cdot 6=12
$$

Result
2 of 2
$$
x=6sqrt{3}
$$

$$
y=12
$$

Exercise 20
Step 1
1 of 2
Rewrite the rational exponents as roots: $x^{1/y}=sqrt[y]{x}$.

a.
$$
125^{2/3}=(sqrt[3]{125})^2=sqrt[3]{5^3})^2=5^2=25
$$

b.
$$
16^{1/2}=sqrt{16}=sqrt{4^2}=4
$$

c.
$$
16^{-1/2}=dfrac{1}{16^{1/2}}=dfrac{1}{sqrt{16}}=dfrac{1}{4}
$$

d.
$$
left( dfrac{1}{81}right)^{1/4}=sqrt[4]{dfrac{1}{81}}=dfrac{sqrt[4]{1}}{sqrt[4]{81}}=dfrac{1}{sqrt[4]{3^4}}=dfrac{1}{3}
$$

Result
2 of 2
a. 25

b. 4

c. $frac{1}{4}$

d. $frac{1}{3}$

Exercise 21
Step 1
1 of 3
Depreciation is represented by an exponential equation:
$$
y=ab^t
$$
with $y$ the value of the car and $t$ the time.

$a$ is the initial value and thus $a=35,000$.

Using the information we then obtain:

$$
21,494=35,000(b)^3
$$

Divide both sides of the equation by 35,000:

$$
dfrac{21,494}{35,000}=(b)^3
$$

Take the cube root of both sides of the equation:

$$
0.85approx sqrt[3]{dfrac{21,494}{35,000}}=b
$$

Replace $a$ in the general equation $y=ab^t$ with 35,000 and $b$ with 0.85:

$$
y=35,000(0.85)^t
$$

Step 2
2 of 3
The annual rate of depreciation is then 1 decreased by the value of $b$:

$$
100%-0.85=100%-85%=15%
$$

Result
3 of 3
$$
y=35,000(0.85)^t
$$

Depreciation rate: 15%

Exercise 22
Result
1 of 1
Measure $a$ from point $P$ on each leg and this is were the other points are. Or draw a circle with radius $a$ and center $P$, the intersections of the circle with the two lines are then the other two vertices.
Exercise 23
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. Opposite sides of a rhombus are parallel.

c.
$$
overline{PR}cong overline{RP}(text{ Same side})
$$

$$
overline{SR}cong overline{QP}(text{ Sides of rhombus have equal length})
$$

$$
overline{SP}cong overline{QR}(text{ Sides of rhombus have equal length})
$$

$$
Downarrow SSS
$$

$$
triangle RSP cong triangle PQR
$$

d.
$$
Downarrow
$$

$$
angle PRS cong angle RPQ
$$

$$
angle SPRcong angle QRP
$$

$$
Downarrow
$$

$$
overleftrightarrow{PQ}// overleftrightarrow{RS}(text{ alternate interior angles are congruent})
$$

$$
overleftrightarrow{PS}// overleftrightarrow{QR}(text{ alternate interior angles are congruent})
$$

Result
3 of 3
Opposite sides of a rhombus are parallel.
Exercise 24
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. The diagonals of a rhombus intersect in the middle of both diagonals.

c.
$$
angle PTScong angle RTQ(text{ Vertical angles})
$$

$$
overline{PS}cong overline{QR}(text{ Sides of rhombus have equal length})
$$

$$
angle TPScong angle TRQ (triangle PQRcong triangle RSP (SSS))
$$

$$
Downarrow AAS
$$

$$
triangle PTScong triangle RTQ
$$

$$
Downarrow
$$

$$
PT=TR
$$

$$
QT=TS
$$

Result
3 of 3
Diagonals intersect in the middle of both diagonals. Diagonals are perpendicular.
Exercise 25
Result
1 of 1
Diagonals of rhombi intersect in the middle of the diagonals.

Opposite sides of rhombi are parallel.

Exercise 26
Step 1
1 of 2
The midpoint of two point $(x_1,y_1)$ and $(x_2,y_2)$ is
$$
left( dfrac{x_1+x_2}{2}, dfrac{y_1+y_2}{2}right)
$$

Thus for these two points:

$$
M=left( dfrac{0+0}{2}, dfrac{3+11}{2}right)=(0,7)
$$

Exercise scan

Result
2 of 2
$$
(0,7)
$$
Exercise 27
Step 1
1 of 3
a. Factorize:

$$
(x-5)^2=0
$$

Take the square root of both sides of the equation:

$$
x-5=0
$$

Add 5 to both sides of the equation:

$$
x=5
$$

b. Factorize:

$$
0=(3x-1)(x+6)
$$

Zero product property:

$$
3x-1=0text{ or } x+6=0
$$

Solve each equation to $x$:

$$
3x=1text{ or } x=-6
$$

$$
x=dfrac{1}{3}text{ or } x=-6
$$

Step 2
2 of 3
c. Subtract 5 from both sides of the equation:

$$
3x^2-2x-5=0
$$

Factorize:

$$
(x+1)(3x-5)=0
$$

Zero product property:

$$
x+1=0text{ or } 3x-5=0
$$

Solve each equation to $x$:

$$
x=-1text{ or } 3x=5
$$

$$
x=-1text{ or } x=dfrac{5}{3}
$$

d. Factorize:

$$
(4x-3)(4x+3)=0
$$

Zero product property:

$$
4x-3=0text{ or } 4x+3=0
$$

Solve each equation to $x$:

$$
4x=3text{ or } 4x=-3
$$

$$
x=dfrac{3}{4}text{ or } x=-dfrac{3}{4}
$$

Result
3 of 3
a. $x=5$

b. $x=frac{1}{3}$ and $x=-6$

c. $x=-1$ and $x=frac{5}{3}$

d. $x=frac{3}{4}$ and $x=-frac{3}{4}$

Exercise 28
Step 1
1 of 2
The quadratic formula is
$$
x=dfrac{-bpm sqrt{b^2-4ac}}{2a}
$$

with $a$ the coefficient of $x^2$, $b$ the coefficient of $x$ and $c$ the constant term.

Then we obtain:

$$
x=dfrac{-17pm sqrt{17^2-4(3)(-6)}}{2(3)}=dfrac{-17pm 19}{6}=dfrac{1}{3}text{ or }-6
$$

Result
2 of 2
$x=dfrac{1}{3}$ and $x=-6$
Exercise 29
Step 1
1 of 2
Use $i^2=-1$ and combine like terms:

a.
$$
p+q=(2+5i)+(3-4i)=(2+3)+(5i-4i)=5+i
$$

b.
$$
p-q=(2+5i)-(3-4i)=(2-3)+(5i+4i)=-1+9i
$$

c.
$$
pq=(2+5i)(3-4i)=6+15i-8i-20i^2=6+7i+20=26+7i
$$

Result
2 of 2
a. $5+i$

b. $-1+9i$

c. $26+7i$

Exercise 30
Step 1
1 of 2
a. Since each flip is independent of the other flip, the probability is the product of each probability:

$$
80%cdot 80%=0.8cdot 0.8=0.64=64%
$$

b. Since each flip is independent of the other flip, the probability is the product of each probability:

$$
80% cdot 20%=0.8cdot 0.2=0.16=16%
$$

Result
2 of 2
a. 64%

b. 16%

Exercise 31
Step 1
1 of 3
a. ABCD is a parallelogram.Exercise scan
Step 2
2 of 3
b. The tangent ratio is the opposite side divided by the adjacent rectangular side:

$$
mangle DAB=mangle BCD=tan^{-1}dfrac{2}{1}approx 63text{textdegree}
$$

c. The equation of a line thourgh two points $(x_1,y_1)$ and $(x_2,y_2)$ is:

$$
y-y_1=dfrac{y_2-y_1}{x_2-x_1}(x-x_1)
$$

Then we obtain

$$
AC: y-1=dfrac{3-1}{5-1}(x-1)=dfrac{1}{2}(x-1)
$$

$$
BD: y-3=dfrac{3-1}{2-4}(x-4)=-dfrac{1}{2}(x-4)
$$

We then note that there slopes are $dfrac{1}{2}$ and $-dfrac{1}{2}$. Since the product of the slopes does not equal $-1$, the diagonals are not perpendicular.

d. On the graph we note that the intersection is $(3,2)$.

Result
3 of 3
a. Parallelogram

b. 63$text{textdegree}$

c. No

d. $(3,2)$

Exercise 32
Step 1
1 of 3
The angle of a equilateral triangle are 60$text{textdegree}$. In a 30$text{textdegree}$-60$text{textdegree}$-90$text{textdegree}$ triangle, we know that the shortest leg is half the hypotenuse. The length of the longest leg is the length of the shortest leg multiplied by $sqrt{3}$.

Exercise scan

Step 2
2 of 3
The area of a triangle is the product of the base and the height divided by 2:

$$
AREA=dfrac{12cdot 6sqrt{3}}{2}=36sqrt{3}
$$

Result
3 of 3
$$
36sqrt{3}
$$
Exercise 33
Step 1
1 of 2
Exercise scan
Result
2 of 2
$TUVW$ is a parallelogram

$$
overline{TW}//overline{UV}
$$

$$
a=b
$$

$$
a=c
$$

Exercise 34
Step 1
1 of 2
Exercise scan
Result
2 of 2
2. $overline{TW} / / overline{VU}$

3. Definition of a parallelogram

4. If lines are parallel, then the corresponding angles are equivalent.

5. $a=b$

6. $a=c$

Exercise 35
Step 1
1 of 2
Exercise scan
Result
2 of 2
1. Given

2. $mangle AMP=mangle BMP$

3. $AM=BM$

4. $PM=PM$, Common side

5. $triangle AMPcong triangle BMP$, SAS

6. $AP=BP$

Exercise 36
Result
1 of 1
Opposite angles of a parallelogram are congruent.

A point of the perpendicular bisector of a segment is equidistant from both end points of the segment.

Exercise 37
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b.Exercise scan
Result
3 of 3
a. Use AAS

b. Use SAS

Exercise 38
Step 1
1 of 2
Two-Column Proofs

The two-column proof contains the statements in the first column and the reasons in the second column. This proof contains more explanations than a flow chart, however, it is harder to see which statements follow from which statements than in a flow chart.

Result
2 of 2
The two-column proof contains the statements in the first column and the reasons in the second column. This proof contains more explanations than a flow chart, however, it is harder to see which statements follow from which statements than in a flow chart.
Exercise 39
Step 1
1 of 5
In this exercise, we need to use the given diagram and information to prove that two angles in the diagram are congruent.

We are given the following diagram:

$$text{Figure 1: Given Diagram}$$

*What angle relationships do we have when lines intersect or are cut by a transversal?*

Step 2
2 of 5
When two lines intersect, we have the following relationships:
* **Supplementary angles:** Two or more angles are supplementary if their angle measures add to $180^circ$. Angles that form a straight line are supplementary.
* **Vertical Angles Theorem:** If two angles are vertical angles (which are non-adjacent angles created by two intersecting lines), then they are congruent.

When two parallel lines are cut by a transversal, we also have the following additional angle relationships:

* **Corresponding Angles Theorem:** If two parallel lines are cut by a transversal, then the corresponding angles are congruent.
* **Alternate Interior Angles Theorem:** If two parallel lines are cut by a transversal, then the alternate interior angles are congruent.
* **Same Side Interior Angles Theorem:** If two parallel lines are cut by a transversal, then the same-side interior angles are supplementary.

Step 3
3 of 5
**Plan:**

Before we start the proof, let’s make a plan on how to go from our Given statement to our Prove statement.

It is given that $overline{AD}paralleloverline{EH}$ and $overline{BF}paralleloverline{CG}$. We then know from Figure $1$ that:
* $a=b$ since they are alternate interior angles for $overline{AD}$ and $overline{EH}$ and
* $b=c$ since they are corresponding angles for $overline{BF}$ and $overline{CG}$.

We can also see from Figure $1$ that $c=d$ since they are vertical angles.

Notice we have $a=b=c=d$ so we know by the repeated use of the Substitution Property (or Transitive Property) that $a=d$.

Our plan for the proof is then:
1. State our givens.
2. Use the Alternate Interior Angles Theorem to prove $a$ and $b$ are equal.
3. Use the Corresponding Angles Theorem to prove $b$ and $c$ are equal.
4. Use the Vertical Angles Theorem to prove $c$ and $d$ are equal.
5. Use the Substitution Property to combine $a=b$ and $b=c$ to get $a=c$ and then to combine $a=c$ and $c=d$ to get $a=d$.

Step 4
4 of 5
**Proof:**

| Statements| Reasons|
|–|–|
| 1. $overline{AD}paralleloverline{EH}$|1. Given |
| 2. $a=b$|2. Alternate Interior Angles Theorem |
|3. $overline{BF}paralleloverline{CG}$ |3. Given |
| 4. $b=c$|4. Corresponding Angles Theorem |
| 5. $a=c$|5. Substitution |
| 6. $c=d$|6. Vertical Angles Theorem |
| 7. $a=d$|7. Substitution |

Step 5
5 of 5
**Summary:**

First, we recalled some of the angle relationships created by intersecting lines and parallel lines cut by a transversal. Then we decided which of these relationships was useful for our proof. After applying the appropriate theorems and properties to our diagram, we made a plan on how to go from the Given statement to the Prove statement. Using our plan, we then constructed a two-column proof.

Exercise 40
Step 1
1 of 3
a. The new coordinates are the original coordinates multiplied by the scale factor:

$$
M'(0,0), A'(6,0), X'(6,4.5)
$$

Exercise scan

Step 2
2 of 3
b. The ratios should equal the scale factor:
$$
dfrac{MA’}{MA}=dfrac{6}{8}=dfrac{3}{4}
$$

$$
dfrac{MX’}{MX}=dfrac{7.5}{10}=dfrac{3}{4}
$$

c. The difference in the $x$-coordinates of JK is 6 and the difference in $y$-coordinates is 8, then U is the coordinates of J increased by $dfrac{1}{4}$ the difference in distance:

$$
U=left( 11+dfrac{1}{4}cdot 6, 7+dfrac{1}{4}cdot 8right)=(11+1.5,7+2)=(12.5,9)
$$

Result
3 of 3
a. $M'(0,0), A'(6,0), X'(6,4.5)$

b. (i) $frac{3}{4}$ (ii) $frac{3}{4}$

c. $(12.5,9)$

Exercise 41
Step 1
1 of 2
The sine ratio is the opposite side divided by the hypotenuse:

$$
theta=sin^{-1}dfrac{70}{100}approx 44.4text{textdegree}
$$

Thus the correct answer is B.

Result
2 of 2
B
Exercise 42
Step 1
1 of 2
Add 7 to both sides of the equation:

$$
7=x^2-4x+4
$$

Factorize:

$$
7=(x-2)^2
$$

Take the square root of both sides of the equation:

$$
pm sqrt{7}=x-2
$$

Add 2 to both sides of the equation:

$$
2pm sqrt{7}=x
$$

Thus the roots are $x=2pm sqrt{7}$

Exercise scan

Result
2 of 2
Vertex $(2,-7)$

$x$-intercepts: $(2pm sqrt{7}, 0)$

$y$-intercept: $(0,-3)$

Exercise 43
Step 1
1 of 3
a. Rewrite 16 as a power of 4:

$$
4^{3/2}=(4^2)^{3/4}=16^{3/4}=4^x
$$

The powers should be equal:

$$
x=dfrac{3}{2}
$$

b. Rewrite 8 and 4 as powers of 2:

$$
2^1=(2^{3})^{1/3}=8^{1/3}=4^x=(2^2)^x=2^{2x}
$$

The powers should be equal:

$$
2x=1
$$

Divide both sides of the equation by 2:

$$
x=dfrac{1}{2}
$$

Step 2
2 of 3
c. Rewrite 9 as a power of 3:

$$
3^{4x}=9^2=(3^2)^2=3^4
$$

The powers should be equal:

$$
4x=4
$$

Divide both sides of the equation by 4:

$$
x=1
$$

d. Rewrite $dfrac{1}{2}$ and 4 as powers of 2:

$$
2^{-x}=(2^{-1})^{x}=left( dfrac{1}{2}right)^{x}=4=2^2
$$

The powers should be equal:

$$
-x=2
$$

Divide both sides of the equation by $-1$:

$$
x=-2
$$

Result
3 of 3
a. $x=frac{3}{2}$

b. $x=frac{1}{2}$

c. $x=1$

d. $x=-2$

Exercise 44
Step 1
1 of 2
If the area of a square is 50 square units, then each side of the square is $sqrt{50}=5sqrt{2}$ units.

The longest line segment in a triangle is the diagonal, whose length can be determined using the Pythagorean theorem:

$$
sqrt{(5sqrt{2})^2+(5sqrt{2})^2}=sqrt{50+50}=sqrt{100}=10
$$

Thus the longest line is 10 units long.

Result
2 of 2
$10$ units
Exercise 45
Step 1
1 of 3
a. Complementary angles sum up to 90$text{textdegree}$:

$$
4x-2+x=90
$$

Add 2 to both sides of the equation:

$$
5x=92
$$

Divide both sides of the equation by 5:

$$
x=dfrac{92}{5}=18.4
$$

b. The sum of all angles in a triangle is 180$text{textdegree}$:

$$
2m+3+m+9+m-1=180
$$

Combine like terms:

$$
4m+11=180
$$

Subtract 11 from both sides of the equation:

$$
4m=169
$$

Divide both sides of the equation by 4:

$$
m=dfrac{169}{4}=42.25
$$

Step 2
2 of 3
c. Vertical angles are congruent:

$$
7k-6=3k+18
$$

Subtract $3k$ from both sides of the equation:

$$
4k-6=18
$$

Add 6 to both sides of the equation:

$$
4k=24
$$

Divide both sides of the equation by 4:

$$
k=6
$$

d. The two triangles are similar because of AA. Corresponding sides of similar triangles have the same proportions:

$$
dfrac{x}{8}=dfrac{16}{13}
$$

Multiply both sides of the equation by 8:

$$
x=dfrac{16cdot 8}{13}=dfrac{128}{13}approx 9.8
$$

Result
3 of 3
a. $x=18.4text{textdegree}$

b. $m=42.25text{textdegree}$

c. $k=6text{textdegree}$

d. $x=9.8$

Exercise 46
Step 1
1 of 4
a.Exercise scan
Step 2
2 of 4
b. If the base angles are congruent, then the triangle is isosceles.Exercise scan
Step 3
3 of 4
c.Exercise scan
Result
4 of 4
Use SAS in each case
Exercise 47
Step 1
1 of 2
a. The non-parallel side lengths appear to be equal (sides appear equally long).

b. If the base angles of a trapezoid are congruent, then the non-parallel side lengths are equal.

c.Exercise scan

Result
2 of 2
a. Equal

b. If the base angles of a trapezoid are congruent, then the non-parallel side lengths are equal.

c. Use AA

Exercise 48
Result
1 of 1
If the base angles of a trapezoid are congruent, then the non-parallel side lengths are equal.

The diagonal that bisects the rhombus divides the rhombus in two congruent triangles.

If the base angles of a triangle are congruent, then the triangle is isosceles.

The diagonals of rectangles are congruent.

Exercise 49
Result
1 of 1
Step 3 (substitution) can only be used after $a=b$ and $b=c$ have been found. Thus step 3 should be moved to between step 5 and step 6.
Exercise 50
Result
1 of 1
You can interchange step 1-2 of the statements with step 4-5 without change the logic (because they are the same steps and are both needed to use the substitution step).
Exercise 51
Step 1
1 of 2
a. Yes, because of AA.

b. HR needs to be half the length of AK, because SR is half of SK. Then we also know that SH is half the length of SA and SH is equal to HA.

c. Since SR has to be half SK:

$$
SR=dfrac{20}{2}=10
$$

Determine SH using the Pythagorean theorem:

$$
HA=SH=sqrt{10^2-8^2}=sqrt{36}=6
$$

Result
2 of 2
a. Yes

b. $HR$ is half the length of $AK$, $SH$ is half the length of $SA$, $SH$ has an equal length of $HA$

c. 6

Exercise 52
Step 1
1 of 2
a. False, a rhombus could also have congruent diagonals.

b. True, because the sum of all angles of a quadrilateral is 360$text{textdegree}$ and thus each angle has to be 90$text{textdegree}$.

c. True, because a rhombus has two pair of parallel sides.

d. False, for example a non-square rectangle is also a parallelogram and its diagonals will not bisect the angles.

Result
2 of 2
a. False

b. True

c. True

d. False

Exercise 53
Step 1
1 of 2
Let $x$ be the number of hours and $y$ the temperature:

$$
y=77+3x
$$

$$
y=92-2x
$$

Subtract the two equations:

$$
0=-15+5x
$$

Add 15 to both sides of the equation:

$$
15=5x
$$

Divide both sides of the equation by 5:

$$
3=x
$$

Determine $y$:

$$
y=77+3x=77+3(3)=77+9=86
$$

Thus 3 hours from now it will be 86$text{textdegree}$ F in both towns.

Result
2 of 2
3 hours from now
Exercise 54
Step 1
1 of 2
The $y$-intercepts is the constant term of the equation and thus is $y=2$.

Let $x$ be 0:

$$
0=x^2+3x+2
$$

Factorize:

$$
0=(x+1)(x+2)
$$

Zero product property:

$$
x+1=0text{ or }x+2=0
$$

Solve each equation to $x$:

$$
x=-1text{ or }x=-2
$$

Thus the $x$-intercepts then have to be $x=-1$ and $x=-2$.

Exercise scan

Result
2 of 2
$x$-intercepts: $(-1,0)$ and $(-2,0)$

$y$-intercept: $(0,2)$

Exercise 55
Step 1
1 of 2
When rotating 90$text{textdegree}$, the $x$ and $y$ coordinates will interchange. If the rotation is also counter-clockwise, then the $x$-coordinate will change sign resulting in point (D).
Result
2 of 2
D
Exercise 56
Step 1
1 of 2
a. The two triangles are similar and since one triangle has lengths that are twice the lengths of the other triangle:

$$
AB=2DE
$$

Moreover these two sides seem to be parallel

b. The midsegment of a triangle is half as long as the parallel third side of the triangle.

c. The triangles are similar:

$$
angle C=angle C(text{ shared angle})
$$

$$
dfrac{CD}{CA}=dfrac{1}{2}(overline{DE}text{ is the midsegment })
$$

$$
dfrac{CE}{CB}=dfrac{1}{2}(overline{DE}text{ is the midsegment })
$$

$$
Downarrow SAS
$$

$$
triangle ABC sim triangle DEC
$$

d. The ratio is $dfrac{1}{2}$, as determined in the proof. Then we obtain:

$$
dfrac{DE}{AB}=dfrac{1}{2}
$$

e. Since the two triangles are similar:

$$
angle Dcong angle A
$$

Since they are corresponding angles, the lines then have to be parallel.

Result
2 of 2
a. Parallel, $AB=2DE$

b. Midsegment is half as long as the parallel third side of the triangle.

c. Use SAS

d. $frac{1}{2}$

e. $angle Dcong angle A$

Exercise 57
Step 1
1 of 2
a. $triangle ABC$, $triangle DBA$ and $triangle DAC$, they are similar because of AA.

b. Yes, because they are corresponding sides in the pair of corresponding triangles.

c. Use cross multiplication and interchange the left and right sides of the equations.

d. We replace the squares with the expressions found in (c).

e. Use distributive property

f.
$$
DB+DC=BC
$$

Thus the expression then becomes:

$$
BC(BC)
$$

g. Because the product of twice the same factor is the square of that factor.

Result
2 of 2
a. AA

b. Yes

c. Cross multiplication

d. Replace squares

e. Distributive property

f. $BC$, $BC(BC)$

g. Product of twice the same factor is the square of that factor.

Exercise 58
Step 1
1 of 2
a. The midpoint of two point $(x_1,y_1)$ and $(x_2,y_2)$ is
$$
left( dfrac{x_1+x_2}{2}, dfrac{y_1+y_2}{2}right)
$$

Thus for these two points:

$$
M=left( dfrac{-4+8}{2}, dfrac{-2+4}{2}right)=(2,1)
$$

b. Add the difference in coordinates multiplied by the given factor to the coordinates of $A$ to obtain the points:

$$
(i) left( -4+dfrac{1}{3}(8+4),-2+dfrac{1}{3}(4+2)right)=(0,0)
$$

$$
(ii) left( -4+dfrac{3}{4}(8+4),-2+dfrac{3}{4}(4+2)right)=(5,2.5)
$$

$$
(iii) left( -4+dfrac{1}{3}(8+4),-2+dfrac{1}{3}(4+2)right)=(0,0)
$$

$$
(iv) left( -4+dfrac{d}{c}(8+4),-2+dfrac{d}{c}(4+2)right)=left( -4+dfrac{12d}{c},-2+dfrac{6d}{c}right)
$$

c. You dilate star B with the given factor and center star A.

d. By determining the difference in the coordinates of the two given points and then adding the product of the fraction and the difference(s) to the corresponding coordinates (of the point where you start).

Result
2 of 2
a. $(2,1)$

b. (i) $(0,0)$ (ii) $(5,2.5)$ (iii) $(0,0)$, (iv) $left(-4+frac{12d}{c}, -2+frac{6d}{c}right)$

c. You dilate star B with the given factor and center star A.

d. By determining the difference in the coordinates of the two given points and then adding the product of the fraction and the difference(s) to the corresponding coordinates (of the point where you start).

Exercise 59
Result
1 of 1
The midsegment of a triangle is parallel to one of the sides and is half the length of this side.

The Pythagorean theorem states: $a^2+b^2=c^2$.

Exercise 60
Step 1
1 of 2
$$
AB=CD(text{Given})
$$

$$
AC=CA(text{ Same side})
$$

$$
angle BACcong angle DCA(text{Alternate interior angles })
$$

$$
Downarrow SAS
$$

$$
triangle BACcong triangle DCA
$$

$$
Downarrow
$$

$$
angle BCAcong angle DAC
$$

$$
Downarrow
$$

$$
overline{BC}//overline{AD}
$$

Result
2 of 2
Use SAS
Exercise 61
Step 1
1 of 4
a. Factorize:
$$
(3x-2)(2x+5)=0
$$

Zero product property:
$$
3x-2=0text{ or } 2x+5=0
$$

Solve each equation to $x$:

$$
3x=2text{ or } 2x=-5
$$

$$
x=dfrac{2}{3}text{ or } x=-dfrac{5}{2}
$$

Step 2
2 of 4
b. The quadratic formula is
$$
x=dfrac{-bpm sqrt{b^2-4ac}}{2a}
$$

with $a$ the coefficient of $x^2$, $b$ the coefficient of $x$ and $c$ the constant term.

Then we obtain:

$$
x=dfrac{-11pm sqrt{11^2-4(6)(-10)}}{2(6)}=dfrac{-11pm 19}{12}=dfrac{2}{3}text{ or }-dfrac{5}{2}
$$

Step 3
3 of 4
c. Yes, as they should because they are solutions of the same equation.
Result
4 of 4
$x=dfrac{2}{3}$ and $x=-dfrac{5}{2}$
Exercise 62
Step 1
1 of 2
Use $i^2=-1$, the distributive property and combine like terms:

$$
(2+i)(3-5i)-(1-4i)^2=6+3i-10i-5i^2-(1-8i+16i^2)
$$

$$
=5+i-21i^2=5+i+21=26+i
$$

Result
2 of 2
$$
26+i
$$
Exercise 63
Step 1
1 of 2
a. Since each flip is independent of the other flip, the probability is the product of each probability:

$$
70%cdot 70%=0.7cdot 0.7=0.49=49%
$$

b. Since each flip is independent of the other flip, the probability is the product of each probability:

$$
70% cdot 30%=0.7cdot 0.3=0.21=21%
$$

Result
2 of 2
a. 49%

b. 21%

Exercise 64
Step 1
1 of 3
a. In a 30$text{textdegree}$-60$text{textdegree}$-90$text{textdegree}$ triangle, we know that the shortest leg is half the hypotenuse. The length of the longest leg is the length of the shortest leg multiplied by $sqrt{3}$.

Exercise scan

Step 2
2 of 3
b. Thus we note that the maximum length of the rope should be
$$
dfrac{10sqrt{3}}{3}approx 5.77 ft
$$
Result
3 of 3
About 5.77 ft
Exercise 65
Step 1
1 of 2
To determine the midpoints you place the point of the compass on point P and draw arcs above and below the segment using the same compass setting, then do the same from point R with again the same compass setting. Then connect the two intersections of the arcs with a line and the intersection of the line with the segment is then the midpoint. Thus (C) is the correct answer.
Result
2 of 2
(C)
Exercise 66
Step 1
1 of 3
a. Factorize the perfect square trinomial:
$$
4x^2-20x+25=(2x-5)^2
$$
b. Quadratic formula to determine roots of quadratic function $y=ax^2+bx+c$:

$$
x=frac{-bpm sqrt{b^2-4ac}}{2a}
$$

Determine the roots of the given equation using the quadratic formula:

$$
begin{align*}
x&=frac{-11pm sqrt{11^2-4(1)(-2)}}{2(1)}
\ &=frac{-11pm sqrt{129}}{2}
end{align*}
$$

The factorization of a quadratic equation is $(x-d)(x-e)$ when $d$ and $e$ are the roots of the equation.

$$
left(x-frac{-11+sqrt{129}}{2}right)left(x-frac{-11-sqrt{129}}{2}right)
$$

Step 2
2 of 3
c. Factor out the greatest common factor:

$$
3x^2-12x=3x(x-4)
$$

d. Factor out the greatest common factor:

$$
10x^2-35x-20=5(2x^2-7x-4)
$$

Factor further:

$$
10x^2-35x-20=5(2x+1)(x-4)
$$

Result
3 of 3
a. $(2x-5)^2$

b. $left(x-frac{-11+sqrt{129}}{2}right)left(x-frac{-11-sqrt{129}}{2}right)$

c. $3x(x-4)$

d. $5(2x+1)(x-4)$

Exercise 67
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. In the diagram we note that you can roll a sum of eight 5 different ways.

c. 1 way out of the 5.

d. The probability is the number of favorable outcomes divided by the number of possible outcomes.

$$
P=dfrac{1}{5}=0.2=20%
$$

e. The probability is the number of favorable outcomes divided by the number of possible outcomes.

$$
P=dfrac{6}{10}=dfrac{3}{5}=0.6=60%
$$

Result
3 of 3
a. Diagram

b. 5 ways

c. 1 way

d. $frac{1}{5}=0.2=20%$

e. $frac{3}{5}=0.6=60%$

Exercise 68
Step 1
1 of 2
a. The probability is the number of favorable outcomes divided by the number of possible outcomes.

$$
P=dfrac{6+34}{6+34+30+170}=dfrac{40}{240}=dfrac{1}{6}approx 0.167=16.7%
$$

b. The probability is the number of favorable outcomes divided by the number of possible outcomes.

$$
P=dfrac{6}{30+6}=dfrac{1}{6}approx 0.167=16.7%
$$

c. Yes, because the probability of a student being on the student council given that the student eats at the cafeteria is equal to the probability of a student being on the student council.

d. No, because these two events can happen at the same time (a student can be on the student council and eat at the cafeteria).

Exercise scan

Result
2 of 2
a. $frac{1}{6}approx 0.167=16.7%$

b. $frac{1}{6}approx 0.167=16.7%$

c. Yes

d. No

Exercise 69
Step 1
1 of 2
a. No, because there are more students who do not have long hair than students who do have long hair.

b. Yes, because there are more students with long hair wearing jeans, then there are students who do not have long hair and wear jeans.

c. Yes, they are associated (not independent) because knowing if a student wears jeans has changed our opinion.

d. No, because they can occur at the same time.

Result
2 of 2
a. No

b. Yes

c. Yes

d. No

Exercise 70
Step 1
1 of 2
a. No, because in the table we note that there is a 0 in the corresponding cell and thus it seems that these two events cannot happen at the same time.

b. Yes, because the two events cannot happen at the same time, since their intersection contains 0 outcomes.

Result
2 of 2
a. No
b. Yes, 0
Exercise 71
Step 1
1 of 2
Independent and Mutually Exclusive

Two events are $textbf{independent}$, if the probability that one event occurs in no way affects the probability of the other event occurring.

Two events are $textbf{disjoint}$ or $textbf{mutually exclusive}$, if the events cannot occur at the same time.

Result
2 of 2
Two events are $textbf{independent}$, if the probability that one event occurs in no way affects the probability of the other event occurring.

Two events are $textbf{disjoint}$ or $textbf{mutually exclusive}$, if the events cannot occur at the same time.

Exercise 72
Step 1
1 of 2
a. The probability is the ratio of the area of the shaded region to the area of the total region:

$$
P=dfrac{2cdot 2}{5cdot 4}=dfrac{4}{20}=dfrac{1}{5}=0.2=20%
$$

b. The probability of not finding the ring is 100%=1 decreased by the probability of finding the ring (since the events are complements of each other):

$$
100%-20%=80%
$$

c. No, because the area of the shaded region has not changed in respect to the area of the original region.

Result
2 of 2
a. $frac{1}{5}=0.2=20%$

b. 80%

c. No

Exercise 73
Step 1
1 of 6
In this exercise, we need to use the given diagram and information to prove that two segments in the diagram are congruent.

*What angle relationships do we have when lines intersect or are cut by a transversal?*

Step 2
2 of 6
When two parallel lines are cut by a transversal, we have the following angle relationships:

* **Corresponding Angles Theorem:** If two parallel lines are cut by a transversal, then the corresponding angles are congruent.
* **Alternate Interior Angles Theorem:** If two parallel lines are cut by a transversal, then the alternate interior angles are congruent.
* **Same Side Interior Angles Theorem:** If two parallel lines are cut by a transversal, then the same-side interior angles are supplementary.

Step 3
3 of 6
The diagram consists of two triangles so the following triangle congruence theorems may also prove useful:
* **SAS:** If two triangles have two pairs of congruent sides and the included angles are also congruent, then the triangles are congruent.
* **SSS:** If two triangles have three pairs of congruent sides, then the triangles are congruent.
* **ASA:** If two triangles have two pairs of congruent angles and the included sides are also congruent, then the triangles are congruent.
* **AAS:** If two triangles have two pairs of congruent angles and a pair of non-included sides are also congruent, then the triangles are congruent.
Step 4
4 of 6
**Plan:**

Before we start the proof, let’s make a plan on how to go from our Given statement to our Prove statement.

It is given that $overline{BC}paralleloverline{EF}$, $overline{AB}paralleloverline{DE}$, and $AF=DC$. Let’s start by labeling the given diagram with all of the congruent alternate interior angles and congruent segments. Recall that a segment is congruent to itself by the Reflexive Property so we can also label $FC$ with tick marks to emphasize this:

$$text{Figure 1: Labeled diagram}$$

From Figure $1$, we can now see that the two triangles have two pairs of congruent angles and a pair of congruent included sides (the bases of the triangles). Therefore, we also know the triangles must be congruent.

Our plan for the proof is then:
1. State our givens.
2. Use the Alternate Interior Angles Theorem to prove the two pairs of angles of congruent.
3. Use the Segment Addition Postulate to prove the bases of the triangles are congruent.
4. Use ASA to prove the triangles are congruent.
5. Conclude the segments are congruent since the triangles are congruent.

Step 5
5 of 6
**Proof:**

| Statements| Reasons|
|–|–|
|1. $overline{BC}paralleloverline{EF}$ | 1. **Given**|
|2. $mangle BCF=mangle EFC$ | 2. **Alternate Interior Angles Theorem**|
|3. $overline{AB}paralleloverline{DE}$| 3. **Given**|
|4. $mangle BAC=mangle EFD$| 4. **Alternate Interior Angles Theorem**|
|5. $AF=DC$|5. **Given**|
|6. $boldsymbol{FC=FC}$|6. Reflexive Property|
|7. $AF+FC=FC+DC$| 7. Addition Property of Equality|
|8. $AC=DC$|8. Segment addition|
|9. $triangle ABCcongtriangle DEF$|9. **ASA**|
|10. $boldsymbol{overline{BC}congoverline{EF}}$|10. $cong;triangletext{s}rightarrowcongtext{ parts}$|

Step 6
6 of 6
**Summary:**

First, we recalled some of the angle relationships created by parallel lines cut by a transversal and the triangle congruence theorems. Then we decided which of these theorems were useful for our proof. After applying the appropriate theorems to our diagram, we made a plan on how to go from the Given statement to the Prove statement. Using our plan, we then constructed a two-column proof.

Exercise 74
Step 1
1 of 2
a. The midpoint of two point $(x_1,y_1)$ and $(x_2,y_2)$ is
$$
left( dfrac{x_1+x_2}{2}, dfrac{y_1+y_2}{2}right)
$$

Then we obtain that $E=(6.5,5)$ (as on the graph).

b. We note that E lies $dfrac{3}{8}$ from A to B.

c.
$$
E=left( 2+dfrac{3}{8}(14-2), 2+dfrac{3}{8}(10-2)right)=(6.5,5)
$$

Exercise scan

Result
2 of 2
a. $(6.5,5)$

b. $frac{3}{8}$

c. $(6.5,5)$

Exercise 75
Step 1
1 of 2
If $x=a$ is an $x$-intercept, then the equation contains a factor $(x-a)$.

a. A possible function is then:

$$
y=left( x-dfrac{3}{4}right)(x+2)=x^2+dfrac{5}{4}x-dfrac{3}{2}
$$

b. A possible function is then:

$$
y=(x+sqrt{5})(x-sqrt{5})=x^2-5
$$

Result
2 of 2
a. $y=x^2+frac{5}{4}x-frac{3}{2}$

b. $y=x^2-5$

Exercise 76
Step 1
1 of 2
a. False, it could also be a trapezium with equal base angles.

b. True

c. True, because if it has three right angles, then the forth angle is also a right angle (using (b)) and thus the quadrilateral is a rectangle.

d. False, the diagonals of a rectangle also bisect each other.

Result
2 of 2
a. False
b. True
c. True
d. False
Exercise 77
Step 1
1 of 2
a. The area of a triangle is the product of the base and the height divided by 2:

$$
AREA=dfrac{2cdot 11}{2}+dfrac{5cdot 10}{2}=11+25=36ft^2
$$

The perimeter is the sum of the lengths of all sides:

$$
5+10+11+2=28ft
$$

b. The area of a triangle is the product of the base and the height divided by 2. The area of a square is one of its sides squared

$$
AREA=dfrac{20cdot 20}{2}+20^2=200+400=600cm^2
$$

The perimeter is the sum of the lengths of all sides:

$$
20+20+20+20+20+(20sqrt{2}-20)=80+20sqrt{2}cm
$$

Exercise scan

Result
2 of 2
a. Area 36 ft$^2$ and Perimeter 28 ft

b. Area 600 cm$^2$ and Perimeter $80+20sqrt{2}$ cm

Exercise 78
Step 1
1 of 2
a. Depreciation is represented by an exponential equation: $y=ab^t$ with $y$ the weight of radioactive material and $t$ the time in hours.

$a$ is the initial value and thus $a=2$.

Using the information we then obtain:

$$
0.45=2(b)^8
$$

Divide both sides of the equation by 2:

$$
0.225=(b)^8
$$

Take the 8throot of both sides of the equation:

$$
0.83approx sqrt[8]{0.225}=b
$$

Thus the equation then becomes:

$$
y=2(0.83)^t
$$

b. The approximate hourly multiplier is 0.83 and the hourly percent of decrease is then:

$$
100%-0.83=100%-83%=17%
$$

c. Evaluate the function at $x=-2$:

$$
y=2(0.83)^{-2}=2.9
$$

Thus about 2.9 grams.

Result
2 of 2
a. $y=2(0.83)^t$

b. $17%$

c. 2.9 grams.

Exercise 79
Step 1
1 of 4
a.Exercise scan
Step 2
2 of 4
b. Add the probabilities from the tree that result in a cow counter:

$$
P(cow)=dfrac{1}{6}+dfrac{1}{20}=dfrac{13}{60}approx 0.217=21.7%
$$

c.Add the probabilities that result in a cow counter:

$$
P(cow)=dfrac{1}{2}cdot dfrac{1}{3}+dfrac{1}{2}cdot dfrac{1}{10}=dfrac{13}{60}approx 0.217=21.7%
$$

Exercise scan

Step 3
3 of 4
d. The probability is the number of favorable outcomes divided by the number of possible outcomes:

$$
P(text{ red given cow})=dfrac{10}{10+1}=dfrac{10}{11}approx 0.909=90.9%
$$

e. No, because the probability of red given cow is not equal to the probability of red (50%).

f. The probability is the number of favorable outcomes divided by the number of possible outcomes:

$$
P(text{ blue given pig})=dfrac{4}{10+4}=dfrac{2}{7}approx 0.286=28.6%
$$

Result
4 of 4
a. Tree diagram

b. $frac{13}{60}approx 0.217=21.7%$

c. $frac{13}{60}approx 0.217=21.7%$

d. $frac{10}{11}approx 0.909=90.9%$

e. No

f. $frac{2}{7}approx 0.286=28.6%$

Exercise 80
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. The probability is the number of favorable outcomes divided by the number of possible outcomes:

$$
P(text{ heads given blue})=dfrac{3}{4}=0.75=75%
$$

Result
3 of 3
a. Tree diagram

b. $frac{3}{4}=0.75=75%$

Exercise 81
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. No, because more students have a car with no regular chores than there are students who have a car with regular chores.
Result
3 of 3
No association
Exercise 82
Step 1
1 of 4
a.Exercise scan
Step 2
2 of 4
b.Exercise scan
Step 3
3 of 4
c. Get the probability from the table in (b): $dfrac{2}{15}approx 0.133=13.3%$.

d. Add the probabilities from the table in (b):

$$
dfrac{4}{10}+dfrac{2}{15}=dfrac{16}{30}approx 0.533=53.3%
$$

e. The probability is the number of favorable outcomes divided by the number of possible outcomes:

$$
dfrac{3}{7}approx 0.429=42.9%
$$

Result
4 of 4
a. Table

b. Table

c. $frac{2}{15}approx 0.133=13.3%$

d. $frac{8}{15}approx 0.533=53.3%$

e. $frac{3}{7}approx 0.429=42.9%$

Exercise 83
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. See in the table: 45%

c. The probability is the number of favorable events divided by the number of possible events:

$$
dfrac{40%}{45%}=dfrac{0.4}{0.45}=dfrac{8}{9}approx 0.889=88.9%
$$

Result
3 of 3
a. Table

b. 45%

c. $frac{8}{9}approx 0.889=88.9%$

Exercise 84
Step 1
1 of 2
a. The probability is the number of favorable events divided by the number of possible events:

$$
dfrac{120}{920}=dfrac{3}{23}approx 0.13=13%
$$

b. The probability is the number of favorable events divided by the number of possible events:

$$
dfrac{12,000}{20,000}=dfrac{3}{5}=0.6=60%
$$

c. Yes, because if they were not associated, the probabilities in (a) and (b) had to be equal.

Result
2 of 2
a. $frac{3}{23}approx 0.13=13%$

b. $frac{3}{5}=0.6=60%$

c. Yes

Exercise 85
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. Corresponding sides of similar triangles have the same proportions:

$$
dfrac{10}{14}=dfrac{x}{22}
$$

Multiply both sides of the equation by 22:

$$
15.7approx dfrac{10cdot 22}{14}=x
$$

Result
3 of 3
$$
overline{DE}=15.7
$$
Exercise 86
Step 1
1 of 2
We know that if the base angles are the same size, then the non-parallel sides of the trapezium will be equally long as well. Thus equation (D) is the only equation that can be true.
$$
3x-2=2x+17
$$
Result
2 of 2
(D) $3x-2=2x+17$
Exercise 87
Step 1
1 of 2
Use the difference of squares factorization: $x^2-a^2=(x-a)(x+a)$.

a.
$$
36x^2-a^2=(6x-a)(6x+a)
$$

b.
$$
16x^4-81=(4x^2-9)(4x^2+9)=(2x-3)(2x+3)(4x^2+9)
$$

Result
2 of 2
a. $(6x-a)(6x+a)$

b. $(2x-3)(2x+3)(4x^2+9)$

Exercise 88
Result
1 of 1
We know that the quadrilateral has one pair of parallel sides and three congruent sides, then the shape can be a square, rhombus, parallelogram or trapezium.
Exercise 89
Step 1
1 of 6
**Concept**
Radicals can be described by the following expression:
$$begin{gather}
^nsqrt{a^m} = a^{frac{m}{n}}
end{gather}$$
Step 2
2 of 6
**Part a**
We evaluate the expression $27^{frac{1}{3}}$ using the property of radicals. We are to find the value of $a$ as shown in Eq (1) as follows:
$$begin{aligned}
&= ^nsqrt{a^m} = a^{frac{m}{n}} \
&= 27^{frac{1}{3}} \
&= ^3 sqrt{27} \
& text{ we know that: }27 = 3^3 \
&= ^3 sqrt{3^3}\
&= boxed{3}
end{aligned}$$

Hence, the expression yields the value $boxed{3}$

Step 3
3 of 6
**Part b**
We evaluate the expression $16^{frac{1}{4}}$ using the property of radicals. We are to find the value of $a$ as shown in Eq (1) as follows:
$$begin{aligned}
&= ^nsqrt{a^m} = a^{frac{m}{n}} \
&= 16^{frac{1}{4}} \
&= ^4 sqrt{16} \
& text{ we know that: }16 = 2^4 \
&= ^4 sqrt{2^4}\
&= boxed{2}
end{aligned}$$

Hence, the expression yields the value $boxed{2}$

Step 4
4 of 6
**Part c**
We evaluate the expression $49^{frac{1}{2}}$ using the property of radicals. We are to find the value of $a$ as shown in Eq (1) as follows:
$$begin{aligned}
&= ^nsqrt{a^m} = a^{frac{m}{n}} \
&= 49^{frac{1}{2}} \
&= ^2 sqrt{49} \
& text{ we know that: }49 = 7^2 \
&= ^2 sqrt{7^2}\
&= boxed{7}
end{aligned}$$

Hence, the expression yields the value $boxed{7}$

Step 5
5 of 6
**Part d**
We evaluate the expression $1000^{frac{1}{3}}$ using the property of radicals. We are to find the value of $a$ as shown in Eq (1) as follows:
$$begin{aligned}
&= ^nsqrt{a^m} = a^{frac{m}{n}} \
&= 1000^{frac{1}{3}} \
&= ^3 sqrt{1000} \
& text{ we know that: }1000 = 10^3 \
&= ^3 sqrt{10^3}\
&= boxed{10}
end{aligned}$$

Hence, the expression yields the value $boxed{10}$

Result
6 of 6
a. $3$
b. $2$
c. $7$
d. $10$
Exercise 90
Step 1
1 of 4
a. Let $x$ be the number of 15-minute periods and $y$ the distance from home.

Exercise scan

Step 2
2 of 4
b. Let $x$ be the number of new gym memberships sold and $y$ the amount earned.

Exercise scan

Step 3
3 of 4
c. Let $x$ be the day of the month and $y$ the amount in the savings account.

Exercise scan

Result
4 of 4
a. Let $x$ be the number of 15-minute periods and $y$ the distance from home.

b. Let $x$ be the number of new gym memberships sold and $y$ the amount earned.

c. Let $x$ be the day of the month and $y$ the amount in the savings account.

Exercise 91
Step 1
1 of 2
a. The probability is the number of favorable events divided by the number of possible events:

$$
dfrac{236}{236+274}=dfrac{236}{510}approx 0.463=46.3%
$$

b. Yes,because if somebody has brought a laptop it is more likely that they are traveling for business.

Result
2 of 2
a. $frac{236}{510}approx 0.463=46.3%$

b. Yes

Exercise 92
Step 1
1 of 3
a. Factorize:

$$
x^2-8x+7=(x-7)(x+1)
$$

b. Factorize:

$$
y^2-2y-15=(y-5)(y+3)
$$

Step 2
2 of 3
c. Factor out the greatest common factor:

$$
7x^2-63=7(x^2-9)
$$

Factorize the difference of squares ($a^2-b^2=(a-b)(a+b)$):

$$
7x^2-63=7(x-3)(x+3)
$$

d. Factorize:

$$
3x^2+10x+8=(3x+4)(x+2)
$$

Result
3 of 3
a. $(x-7)(x+1)$

b. $(y-5)(y+3)$

c. $7(x-3)(x+3)$

d. $(3x+4)(x+2)$

Exercise 93
Step 1
1 of 7
**Concept**
Two exponents with the same base can be evaluated using the following property:
$$begin{gather}
x^n + x^m = x^{(n+m)}
end{gather}$$

On the other hand, radicals can be described by the following expression:

$$begin{gather}
^nsqrt{a^m} = a^{frac{m}{n}}
end{gather}$$

Step 2
2 of 7
**Given**
Evaluate the expression:
$6x^{frac{2}{3}}y^{frac{1}{4}}cdot x^{-1}y^{frac{1}{2}}$

Given that $x=27$ and $y=16$

Step 3
3 of 7
**Solution**
We first plug-in the values of $x$ and $y$ as follows:
$$begin{aligned}
&= 6x^{frac{2}{3}}y^{frac{1}{4}}cdot x^{-1}y^{frac{1}{2}} \
&= 6 cdot27^{frac{2}{3}} cdot 16^{frac{1}{4}}cdot 27^{-1} cdot 16^{frac{1}{2}} \
end{aligned}$$
Step 4
4 of 7
We then combine the exponents with the same bases as follows:
$$begin{aligned}
&= 6 cdot27^{frac{2}{3}} cdot 16^{frac{1}{4}}cdot 27^{-1} cdot 16^{frac{1}{2}} \
&= 6 cdot (27^{frac{2}{3}} cdot 27^{-1}) cdot (16^{frac{1}{4}}cdot 16^{frac{1}{2}}) \
end{aligned}$$
Step 5
5 of 7
Using the property of exponents from Eq (1), we simply the expression as follows:
$$begin{aligned}
&= 6 cdot (27^{frac{2}{3}} cdot 27^{-1}) cdot (16^{frac{1}{4}}cdot 16^{frac{1}{2}}) \
&= 6 cdot (27^{(frac{2}{3} -1)}) cdot (16^{frac{1}{4}+frac{1}{2}}) \
&= 6 cdot (27^{(frac{2}{3} -frac{3}{3})}) cdot (16^{frac{1}{4}+frac{2}{4}}) \
&= 6 cdot (27^{-frac{1}{3}}) cdot (16^{frac{3}{4}}) \
end{aligned}$$
Step 6
6 of 7
Then, we evaluate the value of the radicals using Eq (2) as follows:
$$begin{aligned}
&= 6 cdot (27^{-frac{1}{3}}) cdot (16^{frac{3}{4}}) \
^nsqrt{a^m} &= a^{frac{m}{n}} \
&= 6 cdot left(frac{1}{^3sqrt{27}} right) cdot (^4sqrt{16^3}) \
& text{ we know that: $27= 3^3$ and $16 = 2^4$} \
&= 6 cdot left(frac{1}{^3sqrt{3^3}} right) cdot (^4sqrt{(2^4)^3}) \
&= 6 cdot left(frac{1}{3}right) cdot (2^3) \
&= 6 cdot frac{1}{3} cdot 8 \
&= boxed{16}
end{aligned}$$

The expression $6x^{frac{2}{3}}y^{frac{1}{4}}cdot x^{-1}y^{frac{1}{2}}$ when $x=27$ and $y=16$ yields the value $16$

Result
7 of 7
$16$
Exercise 94
Step 1
1 of 3
a. The sum of all angles in a triangle is 180$text{textdegree}$:

$$
4x+28+x+19+3x+13=180
$$

Combine like terms:

$$
8x+60=180
$$

Subtract 60 from both sides of the equation:

$$
8x=120
$$

Divide both sides of the equation by 8:

$$
x=15
$$

b. The two given sides are congruent:

$$
6k+3=3k+18
$$

Subtract $3k$ from both sides of the equation:

$$
3k+3=18
$$

Subtract 3 from both sides of the equation:

$$
3k=15
$$

Divide both sides of the equation by 3:

$$
k=5
$$

Step 2
2 of 3
c. Opposite angles of a parallelogram are congruent:

$$
4t+13=8t-23
$$

Subtract $4t$ from both sides of the equation:

$$
13=4t-23
$$

Add 23 to both sides of the equation:

$$
36=4t
$$

Divide both sides of the equation by 4:

$$
9=t
$$

Adjacent angles of a parallelogram are supplementary:

$$
w=180-(4t+13)=180-4(9)-13=131
$$

d. The sine ratio is the opposite side divided by the hypotenuse:

$$
sin{35.5text{textdegree}}=dfrac{x/2}{43}
$$

Multiply both sides of the equation by 86:

$$
50approx 86sin{35.5text{textdegree}}=x
$$

Result
3 of 3
a. $x=15text{textdegree}$

b. $k=5$

c. $t=9text{textdegree}$ and $w=131text{textdegree}$

d. $x=50$

Exercise 95
Step 1
1 of 2
a. Multiply both sides of the equation by $r^2$:

$$
Fr^2=GmM
$$

Divide both sides of the equation by $F$:

$$
r^2=dfrac{GmM}{F}
$$

Take the square root of both sides of the equation:

$$
r=sqrt{dfrac{GmM}{F}}
$$

b. Divide both sides of the equation by $rF$:

$$
dfrac{tau}{rF}=sin{theta}
$$

Take the inverse sine of both sides of the equation:

$$
sin^{-1}{dfrac{tau}{rF}}=theta
$$

Interchange left and right side of the equation:

$$
theta =sin^{-1}{dfrac{tau}{rF}}
$$

Result
2 of 2
a. $r=sqrt{frac{GmM}{F}}$

b. $theta=sin^{-1}frac{tau}{rF}$

Exercise 96
Step 1
1 of 2
a. The distance between two points $(x_1,y_1)$ and $(x_2,y_2)$ is given by the distance formula:

$$
sqrt{(x_2-x_1)^2+(y_2-y_1)^2}
$$

Evaluate for the given points:

$$
sqrt{(5-1)^2+(2-6)^2}=sqrt{16+16}=sqrt{32}=4sqrt{2}
$$

b. ABB’A’ is a trapezium and the area of a trapezium is the sum of the bases multiplied by the height, divided by 2:

$$
AREA=dfrac{(2+10)4}{2}=24
$$

Exercise scan

Result
2 of 2
a. $4sqrt{2}$

b. 24

Exercise 97
Step 1
1 of 3
a. Take the square root of both sides of the equation:

$$
x+4=pm 7
$$

Subtract 4 from both sides of the equation:

$$
x=-4pm 7=3text{ or }-11
$$

b. Divide both sides of the equation by 3:

$$
sqrt{x+2}=4
$$

Square both sides of the equation:

$$
x+2=16
$$

Subtract 2 from both sides of the equation:

$$
x=14
$$

Step 2
2 of 3
c. Subtract $dfrac{3}{10}$ from both sides of the equation:

$$
dfrac{2}{x}=dfrac{10}{10}=1
$$

Multiply both sides of the equation by $x$:

$$
2=x
$$

d. Add 2 to both sides of the equation:

$$
5(2x-1)=15
$$

Divide both sides of the equation by 5:

$$
2x-1=3
$$

Add 1 to both sides of the equation:

$$
2x=4
$$

Divide both sides of the equation by 2:

$$
x=2
$$

Result
3 of 3
a. $x=-11$ or $x=3$

b. $x=14$

c. $x=2$

d. $x=2$

Exercise 98
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. Read the probability from the table: $0.25=25%$

c. Add the corresponding probabilities:

$$
0.25+0.08+0.1=0.43=43%
$$

d. Yes, because the relationship between EAT and EX in the column is higher than either column/row being No.

Result
3 of 3
a. Table

b. $0.25=25%$

c. $0.43=43%$

d. Yes

Exercise 99
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. Add the corresponding probabilities:

$$
P(win)=dfrac{1}{64}+dfrac{1}{16}+dfrac{1}{16}+dfrac{9}{64}=dfrac{9}{32}approx 28.125=28.125%
$$

c. The probability is the number of favorable outcomes divided by the number of possible outcomes:

$$
P(100|win)=dfrac{1/64}{9/32}=frac{1}{18}approx 0.055=5.5%
$$

d.
$$
P(100|win)=dfrac{P(100text{ and }win)}{P(win)}=dfrac{1/64}{9/32}=dfrac{1}{18}approx 0.055=5.5%
$$

Result
3 of 3
a. Table

b. $frac{9}{32}approx 0.28125=28.125%$

c. $frac{1}{18}approx 0.055=5.5%$

d. $frac{1}{18}approx 0.055=5.5%$

Exercise 100
Step 1
1 of 2
a. The multiplication rule is:

$$
P(Atext{ given }B)=dfrac{P(Atext{ and }B)}{P(B)}
$$

Multiply both sides of the equation by $P(B)$ and interchange the left and right side of the equation:

$$
P(Atext{ and }B)=P(B)cdot P(Atext{ given }B)
$$

b. If $A$ and $^B$ are independent:

$$
P(Atext{ given }B)=P(A)
$$

c. Substitute $P(AgivenB)$ with $P(A)$ in the equation of (a):

$$
P(Atext{ and }B)=P(B)cdot P(A)
$$

d. Yes, when determining the probability of two events at the same time (which were independent).

Result
2 of 2
a. $P(Atext{ and }B)=P(B)cdot P(Atext{ given }B)$

b. $P(Atext{ given }B)=P(A)$

c. $P(Atext{ and }B)=P(B)cdot P(A)$

d. Yes

Exercise 101
Step 1
1 of 2
Let $A$ be bats and $B$ be balls. Using the multiplication rule we get:

$$
P(AgivenB)=dfrac{P(AandB)}{P(A)}=dfrac{72/240}{180/240}=dfrac{2}{5}=0.4=40%
$$

While we know that:

$$
P(A)=dfrac{180}{240}=dfrac{3}{4}=0.75=75%
$$

Thus we note that $P(Agiven B)neq P(A)$ and thus the two events are associated.

Result
2 of 2
Yes
Exercise 102
Step 1
1 of 2
a. Since the events are independent:

$$
P(text{ heads and truth})=dfrac{1}{2}cdot dfrac{1}{6}=dfrac{1}{12}approx 0.083=8.3%
$$

b.
$$
P(heads)=P(text{ heads and truth})+P(text{ heads and lie})
$$

$$
=dfrac{1}{12}+dfrac{1}{2}cdot dfrac{5}{6}=dfrac{1}{12}+dfrac{5}{12}=dfrac{1}{2}=0.5=50%
$$

c. Since the events are independent:

$$
P(truth|heads)=P(truth)=dfrac{1}{6}=0.167=16.7%
$$

d. Independent because flipping a coin and rolling a dice is independent (they cannot influence each other).

Result
2 of 2
a. $frac{1}{12}approx 0.083=8.3%$

b. $frac{1}{2}=0.5=50%$

c. $frac{1}{6}approx 0.167=16.7%$

d. Independent

Exercise 103
Step 1
1 of 2
Since the rows and columns have to be independent, we know that of the 70 that have a below average IQ $dfrac{50}{175}$ need to have a below average height (because the ratios have to be the same for all columns and also have to be the same for all rows):

$$
70cdot dfrac{50}{175}=20
$$

The remaining numbers can be found by makings sure the totals at the right and bottom are correct.

Exercise scan

Result
2 of 2
20, 50, 30, 75
Exercise 104
Step 1
1 of 3
a. The probability that it will land on red is 100% decreased by the probability that it will land on blue (because in total the probability is 100%):

$$
P(red)=100%-x=1-x
$$

b.

Exercise scan

Step 2
2 of 3
c. Add the corresponding probabilities:

$$
P(same color)=(1-x)^2+x^2
$$

d. Use the multiplication rule:
$$
P(blue|same color)=dfrac{P(BLUE and SAME COLOR)}{P(BLUE)}=dfrac{x^2}{x}=x
$$

Result
3 of 3
a. $1-x$

b. Area model

c. $(1-x)^2+x^2$

d. $x$

Exercise 105
Step 1
1 of 4
a. The probability that it will not land on blue is 100% decreased by the probability that it will land on blue (because in total the probability is 100%):

$$
P(green)+P(red)=100%-x=1-x
$$

Since green and red have equal probability:

$$
P(green)=P(red)=dfrac{1-x}{2}
$$

b.

Exercise scan

Step 2
2 of 4
c.Exercise scan
Step 3
3 of 4
d. Add the corresponding probabilities:

$$
P(same color)=dfrac{(1-x)^2}{4}+x^2+dfrac{(1-x)^2}{4}=dfrac{(1-x)^2}{2}+x^2
$$

e. Use the multiplication rule:
$$
P(blue|same color)=dfrac{P(BLUE and SAME COLOR)}{P(SAME COLOR)}=dfrac{x^2}{dfrac{(1-x)^2}{2}+x^2}
$$

Result
4 of 4
a. $frac{1-x}{2}$

b. Model

c. Shaded region

d. $frac{(1-x)^2}{2}+x^2$

e. $frac{x^2}{frac{(1-x)^2}{2}+x^2}$

Exercise 106
Step 1
1 of 2
Probability rules

The addition rule: P(A or B)=P(A)+P(B)-P(A and B)

The multiplication rule: P(A given B)=P(A and B)/P(B)

Other version multiplication rule: P(A and B)=P(A)P(A given B)

Independence rule: P(A given B)=P(A)

Other independence rule: P(A and B)=P(A)P(B)

Result
2 of 2
The addition rule: P(A or B)=P(A)+P(B)-P(A and B)

The multiplication rule: P(A given B)=P(A and B)/P(B)

Other version multiplication rule: P(A and B)=P(A)P(A given B)

Independence rule: P(A given B)=P(A)

Other independence rule: P(A and B)=P(A)P(B)

Exercise 107
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. Add the corresponding probabilities:

$$
P(either)=0.25+0.12+0.4=0.77=77%
$$

c. Use the multiplication rule:
$$
P(daily|either)=dfrac{P(DAILYand EITHER)}{P(EITHER)}=dfrac{0.65}{0.77}approx 0.844=84.4%
$$

Result
3 of 3
a. Table

c. 0.77=77%

c. 0.844=84.4%

Exercise 108
Step 1
1 of 2
Use the multiplication rule:
$$
P(FineArts|academic)=dfrac{P(FINEARTSand ACADEMIC)}{P(ACADEMIC)}=dfrac{8/768}{128/768}=dfrac{8}{128}=dfrac{1}{16}=0.0625=6.25%
$$

Compare with the probability of the fine arts alone:

$$
P(FineArts)=dfrac{48}{768}=dfrac{1}{16}=0.0625=6.25%
$$

We note that the two probabilities are equal and thus Dr. G has nothing to worrty about because the two events are independent.

Result
2 of 2
No
Exercise 109
Step 1
1 of 2
Add 10.25 to both sides of the equation:

$$
10.25=x^2+7x+12.25
$$

Factorize:

$$
10.25=(x+3.5)^2
$$

Take the square root of both sides of the equation:

$$
pm 0.5sqrt{41}=pm sqrt{10.25}=x+3.5
$$

Subtract 3.5 from both sides of the equation:

$$
-0.3text{ or } -6.7approx -3.5pm 0.5sqrt{41}=x
$$

Thus the solutions are $x=-3.5pm 0.5sqrt{41}$.

The $y$-intercept is $y=2$ and the vertex is $(-3.5,-10.25)$ which is a minimum.

Exercise scan

Result
2 of 2
Vertex $(-3.5,-10.25)$

$y$-intercept: $(0,2)$

Minimum

Exercise 110
Step 1
1 of 2
The base angles of an isosceles triangle are congruent and thus equation (B) is correct.
Result
2 of 2
B
Exercise 111
Step 1
1 of 3
a. Rewrite 4 and 8 as a power of 2:

$$
2^{2z}=(2^2)^z=4^z=2^3
$$

The powers have to be equal:

$$
2z=3
$$

Divide both sides of the equation by 2:

$$
z=dfrac{3}{2}
$$

b. Rewrite 4 and 8 as a power of 2:

$$
2^{10z}=(2^2)^{5z}=4^{5z}=8^{z+2}=(2^3)^{z+3}=2^{3(z+3)}
$$

The powers have to be equal:

$$
10z=3z+9
$$

Subtract $3z$ from both sides of the equation:

$$
7x=9
$$

Divide both sides of the equation by 7:

$$
z=dfrac{9}{7}
$$

Step 2
2 of 3
c. Rewrite 81 as a power of 3:

$$
3^z=81^2=(3^4)^2=3^8
$$

The powers have to be equal:

$$
z=8
$$

d. Rewrite 25 as a power of 5:

$$
5^{(z+1)/3}=25^z=(5^2)^z=5^{2z}
$$

The powers have to be equal:

$$
dfrac{1}{3}z+dfrac{1}{3}=2z
$$

Subtract $dfrac{1}{3}z$ from both sides of the equation:

$$
dfrac{1}{3}=dfrac{5}{3}z
$$

Multiply both sides of the equation by $dfrac{3}{5}$:

$$
dfrac{1}{5}=z
$$

Result
3 of 3
a. $z=frac{3}{2}$

b. $z=frac{9}{7}$

c. $z=8$

d. $z=frac{1}{5}$

Exercise 112
Result
1 of 1
Draw a line segment. Draw an arc with the passer above the segment with the needle located at an endpoint. Then repeat this for the other endpoint with the same passer width. The intersection of the two arcs is then the third vertex of the triangle.
Exercise 113
Step 1
1 of 2
a. The triangle is an isosceles right triangle since:

$$
AC=sqrt{(6-3)^2+(4-0)^2}=5=sqrt{(2-6)^2+(7-4)^2}=BC
$$

and the slope of $overline{AC}$is $dfrac{4-0}{6-3}=dfrac{4}{3}$ while the slope of $overline{BC}$ is $dfrac{2-6}{7-4}=-dfrac{3}{4}$, then we know that $overline{AC}$ and $overline{BC}$ are perpendicular (since the product of the slopes is $-1$).

b. The tangent ratio is the opposite side divided by the adjacent rectangular side:

$$
mangle A=tan^{-1}dfrac{5}{5}=tan^{-1}1=45text{textdegree}
$$

c. The tangent ratio is the opposite side divided by the adjacent rectangular side:

$$
tan{45text{textdegree}}=dfrac{5}{5}=1
$$

Exercise scan

Result
2 of 2
a. Isosceles right triangle

b. 45$text{textdegree}$

c. 1

Exercise 114
Step 1
1 of 2
a. The probability is the number of favorable outcomes divided by the number of possible outcomes:

$$
P(able)=dfrac{9+3}{9+3+36+12}=dfrac{12}{60}=dfrac{1}{5}=0.2=20%
$$

b. The probability is the number of favorable outcomes divided by the number of possible outcomes:

$$
P(music AND able)=dfrac{3}{60}=dfrac{1}{20}=0.05=5%
$$

c. Use the multiplication rule:
$$
P(able GIVEN music)=dfrac{P(musicANDable)}{P(able)}=dfrac{39/60}{0.2}=0.13=13%
$$

Since this probability is not equal to $P(able)$ we then know that the events are NOT independent.

Result
2 of 2
a. $frac{1}{5}=0.2=20%$

b. $frac{1}{20}=0.05=5%$

c.Not independent

Exercise 115
Step 1
1 of 2
$$
BC=CD
$$

$$
AB=CE(text{ Pythagorean theorem})
$$

$$
angle Bcong angle C
$$

$$
Downarrow SAS
$$

$$
triangle ABCcong triangle ECD
$$

Since corresponding sides of congruent triangles are equal:

$$
x=41-9=32
$$

Result
2 of 2
$$
x=32
$$
Exercise 116
Step 1
1 of 2
Since the sum of all angles in a triangle is 180$text{textdegree}$ and supplementary angles sum up to 180$text{textdegree}$, we then kow that $mangle ABD=74text{textdegree}+79text{textdegree}=150text{textdegree}$ and thus (D) is the correct answer.
Result
2 of 2
D
Exercise 117
Step 1
1 of 2
The axis of symmetry of the given function (equation) is:

$$
x=-dfrac{b}{2a}=-dfrac{5}{2(-1)}=dfrac{5}{2}=2.5
$$

The maximum value is then the corresponding $y$-value:

$$
y=-(2.5)^2+5(2.5)+6=12.25
$$

Thus we note that this maximum is higher than the maximum on the graph ($y=2$).

Result
2 of 2
$$
y=-x^2+5x+6
$$
Exercise 118
Step 1
1 of 3
a. Add 49 to both sides of the equation:

$$
49=x^2+8x+16
$$

Factorize:

$$
49=(x+4)^2
$$

Take the square root of both sides of the equation:

$$
pm 7=x+4
$$

Subtract 4 from both sides of the equation:

$$
3text{ or }-11=-4pm 7=x
$$

b. Subtract 4 from both sides of the equation:

$$
x^2-2x+1=-4
$$

Factorize:

$$
(x-1)^2=-4
$$

Take the square root of both sides of the equation:

$$
x-1=2i
$$

Add 1 to both sides of the equation:

$$
x=1+2i
$$

Step 2
2 of 3
c. Add 15.25 to both sides of the equation:

$$
x^2-7x+12.25=15.25
$$

Factorize:

$$
(x-3.5)^2=15.25
$$

Take the square root of both sides of the equation:

$$
x-3.5=pm sqrt{15.25}=pm 0.5sqrt{61}
$$

Add 3.5 to both sides of the equation:

$$
x=3.5pm 0.5sqrt{61}
$$

Result
3 of 3
a. $x=3$ or $x=-11$

b. $x=1+2i$

c. $x=3.5pm 0.5sqrt{61}$

Exercise 119
Step 1
1 of 2
Exercise scan
Result
2 of 2
$$
m^{1/2}n^{1/2}
$$

Power of product property

$$
sqrt{mn}
$$

Exercise 120
Step 1
1 of 2
Multiply the first equation by $-5$:

$$
-5y=15x+10
$$

$$
2x+5y=16
$$

Add the two equations:

$$
2x=16+15x+10
$$

Subtract $15x$ from both sides of the equation:

$$
-13x=26
$$

Divide both sides of the equation by $-13$:

$$
x=-2
$$

Determine $y$:

$$
y=-3x-2=-3(-2)-2=6-2=4
$$

Thus the solution is $(-2,4)$.

Result
2 of 2
$$
(-2,4)
$$
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