Core Connections Integrated 1
Core Connections Integrated 1
2nd Edition
Brian Hoey, Judy Kysh, Leslie Dietiker, Tom Sallee
ISBN: 9781603283236
Textbook solutions

All Solutions

Page 109: Closure Activity

Exercise 113
Step 1
1 of 2
$textbf{a.}$

Use any two points, say $(0,1)$ and $(2, 0)$ so that $Delta x=2-0=2$ and $Delta y=0-1=-1$. So, the slope is:

$$
m=dfrac{Delta y }{Delta x}=dfrac{-1}{2}=color{#c34632}-dfrac{1}{2}
$$

$textbf{b.}$

The $y$-intercept is where the graph intersects the $y$-axis. In this case, at:

$$
color{#c34632}(0,1)
$$

$textbf{c.}$

Use the equation of the line in the form $y=mx+b$ where $m=-dfrac{1}{2}$ (slope) and $b=1$ ($y$-intercept):

$$
color{#c34632}y=-dfrac{1}{2}x+1
$$

Result
2 of 2
a. $-dfrac{1}{2}$

b. $(0,1)$

c. $y=-dfrac{1}{2}x+1$

Exercise 114
Step 1
1 of 2
$textbf{a.}$

In the equation of a line $y=mx+b$, $m$ represents the slope and $b$ represents the $y$-intercept. In this case,

$$
color{#c34632}m=2,b=1
$$

$textbf{b.}$

In the equation of a line $y=mx+b$, $m$ represents the slope and $b$ represents the $y$-intercept. In this case,

$$
color{#c34632}m=dfrac{2}{5},b=-4
$$

Result
2 of 2
a. $m=2,b=1$

b. $m=dfrac{2}{5},b=-4$

Exercise 115
Step 1
1 of 3
The method I used to graph the lines is to use the slope and $y$-intercept that we found in the previous question.

$textbf{a.}$

We have:

$$
m=2,b=1
$$

First, we plot the $y$-intercept, $(0,1)$. From this point, we locate another point by using the slope. That is, we move 2 units up and 1 unit to the right, locating $(1,3)$. Then, connect the two points with a straight line:

Exercise scan

Step 2
2 of 3
$textbf{b.}$

We have:

$$
m=dfrac{2}{5},b=-4
$$

First, we plot the $y$-intercept, $(0,-4)$. From this point, we locate another point by using the slope. That is, we move 2 units up and 5 units to the right, locating $(5,-2)$. Then, connect the two points with a straight line:

Exercise scan

Result
3 of 3
Hint: The method I used to graph the lines is to use the slope and $y$-intercept that we found in the previous question.
Exercise 116
Step 1
1 of 7
Using

$$
a^m cdot a^n=a^{m+n}
$$

$$
dfrac{a^m}{a^n}=a^{m-n}
$$

$$
(a^m)^n=a^{mn}
$$

$$
a^{-n}=dfrac{1}{a^n}
$$

Step 2
2 of 7
a)
$$
dfrac{14a^3b^2}{21a^4b}=dfrac{14}{21} cdot a^{3-4}b^{2-1}=
dfrac{2}{3} cdot a^{-1}b^1=dfrac{2}{3}cdot dfrac{1}{a} cdot b=dfrac{2b}{3a}
$$
Step 3
3 of 7
b)
$$
2m^3n^2 cdot 3mn^4=6m^{3+1}n^{2+4}=6m^4n^6
$$
Step 4
4 of 7
c)
$$
dfrac{4x^{18}}{(2x^{22})^0}=dfrac{4x^{18}}{1}=4x^{18}
$$

(Using $a^0=1$)

Step 5
5 of 7
d)
$$
(s^4tu^2)(s^7t^{-1})=s^{4+7}t^{1+(-1)}u^2=s^{11}t^0u^2=s^{11}u^2
$$
Step 6
6 of 7
e)

$$
(3w^{-2})^4=3^4 w^{-2 cdot 4}=81 w^{-8}=dfrac{81}{w^8}
$$

Step 7
7 of 7
f)
$$
m^{-3}=dfrac{1}{m^3}
$$
Exercise 117
Step 1
1 of 2
Given that, Shirley starts with $85 in the bank and saves $15 every two months.\\
Unit rate of change in the situation is given as $15 every two months, which is equal to slope of the line we intend to find.$ $text{Slope}=dfrac{15}{2}=7.5 dfrac{text{Dollars}}{text{month}}$ $\
Let$x$represents the months and$y$represent the money in $ in Shirley’s bank account in any given month, then the equation of line is can be written as$ $y=mx+c$ $where,$m$is the slope of the line and c is the$y$- intercept.\
We are given the slope as$7.5$and$c=$85$ is the y-intercept as it represent the account balance for starting month which is $x=0$. On putting these values into the equation, the final equation becomes

$$
y=7.5x+85
$$

Result
2 of 2
$$
y=7.5x+85
$$
Exercise 118
Step 1
1 of 2
Slope of a line which passes through a pair or points $(x_1,y_1)$ and $(x_2,y_2)$ is given by

$$
text{slope}=dfrac{y_2-y_1}{x_2-x_1}
$$

We can choose any two set of points from the table to find the slope.

$textbf{(a)}$ Let $(x_1,y_1)=(0,9)$ and $(x_2,y_2)=(1,4)$, therefore slope of line passing through these point is
$$
begin{align*}
text{slope}&= dfrac{4-9}{1-0}\
&=dfrac{-5}{1}\
&=-5
end{align*}
$$

$textbf{(b)}$ Let $(x_1,y_1)=(2,22)$ and $(x_2,y_2)=(4,40)$, therefore slope of line passing through these point is
$$
begin{align*}
text{slope}&= dfrac{40-22)}{4-2}\
&=dfrac{18}{2}\
&=9
end{align*}
$$

Result
2 of 2
$textbf{(a)}$ -5

$textbf{(b)}$ 9

Exercise 119
Step 1
1 of 2
Let $x$ be the figure number and $y$ be the number of tiles so that the three figures correspond to the points:

$$
(1,6),(2,9),(3,12)
$$

Using any two points, say $(1,6)$ and $(2,9)$, we have $Delta x=2-1=1$ and $Delta y=9-6=3$. So, the slope is:

$$
m=dfrac{Delta y }{Delta x}=dfrac{3}{1}=3
$$

Use the equation of the line in the form $y=mx+b$. Substituting any of the two points and the slope, we can solve for $b$. I used $(x,y)=(1,6)$:

$$
begin{align*}
y&=mx+b\
6&=3(1)+b\
6&=3+b\
3&=b\
end{align*}
$$

So, the equation of the line (rule for the tile pattern) is:

$$
color{#c34632}y=3x+3
$$

For figure 58, $x=58$, there are:

$$
y=3(58)+3=174+3=color{#c34632}177text{ tiles}
$$

Result
2 of 2
$y=3x+3$ where $x$ is the figure number and $y$ is the number of tiles ; 177 tiles
Exercise 120
Step 1
1 of 3
Exercise scan
Step 2
2 of 3
Exercise scan
Result
3 of 3
Exercise 121
Solution 1
Solution 2
Step 1
1 of 2
Slope of line passing through 2 given points $(x_1,y_1)$ and $(x_2,y_2)$ can be written as

$$
text{slope}=dfrac{y_2-y_1}{x_2-x_1}
$$

Now, we have points as $(-5,7)$ and $(10,1)$

$Rightarrow$
$$
begin{align*}
text{slope}&=dfrac{1-7}{10-(-5)}\
&=dfrac{-6}{15}\
&=dfrac{-2}{5}\
end{align*}
$$

Result
2 of 2
$$
-dfrac{2}{5}
$$
Step 1
1 of 2
slope = $dfrac{y2-y1}{x2-x1}$ = $dfrac{1-7}{10-(-5)}$ = $dfrac{-6}{15}$ = $dfrac{-2}{5}$
Result
2 of 2
-2/5
Exercise 122
Step 1
1 of 6
$$
{color{#4257b2}text{ a) }}
$$

$$
begin{align*}
& text{For x=-2 we solve this}\
&-3left(-2right)^2+4left(-2right)+5\\
&=-3cdot :4+4left(-2right)+5 tag{Calculate exponents} \
&=-12+4left(-2right)+5 tag{Multiply and Divide}\
&=-12-8+5 tag{Multiply and Divide}\\
&=boxed{{color{#c34632} -15 } }
end{align*}
$$

Step 2
2 of 6
$$
{color{#4257b2}text{ b) }}
$$

$$
begin{align*}
& text{For x=1 we solve this}\
&6-left(5cdot :1-9right)^2\\
&=6-left(-4right)^2 tag{Calculate within parentheses} \
&=6-16 tag{Calculate exponents}\\
&=boxed{{color{#c34632} -10 } }
end{align*}
$$

Step 3
3 of 6
$$
{color{#4257b2}text{ c) }}
$$

$$
begin{align*}
& text{For k=-8 we solve this}\
&frac{-4}{-8+7}\\
&=frac{-4}{-1} tag{Add/Subtract the numbers} \
&=frac{4}{1}\\
&=boxed{{color{#c34632} 4 } }
end{align*}
$$

$$
color{#c34632} text{}mathrm{Apply:the:fraction:rule}:quad frac{-a}{-b}=frac{a}{b}
$$

$$
color{#c34632} text{} mathrm{Apply:rule}:frac{a}{1}=a
$$

$$
text{}
$$

Step 4
4 of 6
$$
{color{#4257b2}text{ d) }}
$$

$$
begin{align*}
& text{For m=-2 and n=3 we solve this}\
&frac{2left(-2right)}{3-1}-left(-2right)^3-3\\
&=frac{-2cdot :2}{3-1}-left(-2right)^3-3 tag{Remove parentheses} \
&=-2-left(-2right)^3-3\
&=-2-left(-2^3right)-3\
&=-2+2^3-3 \
&=2^3-5 \
&=8-5 \\
&=boxed{{color{#c34632} 3 } }
end{align*}
$$

$$
color{#c34632} text{}mathrm{Apply:exponent:rule}:quad left(-aright)^n=-a^n,:mathrm{if:}nmathrm{:is:odd}
$$

$$
color{#c34632} text{} mathrm{Apply:rule}:-left(-aright)=a
$$

$$
text{}
$$

Step 5
5 of 6
$$
{color{#4257b2}text{ e) }}
$$

$$
begin{align*}
& text{K, can not equal to -7 because denominator can not be 0 }
end{align*}
$$

Result
6 of 6
$$
color{#4257b2} text{a)}-15
$$

$$
color{#4257b2} text{b)}-10
$$

$$
color{#4257b2}text{c)} 4
$$

$$
color{#4257b2} text{d)} 3
$$

$$
color{#4257b2} text{e)K, can not equal to -7 because denominator can not be 0}
$$

Exercise 123
Step 1
1 of 2
Given that a page contains an average of 300 words and it takes someone to read one page in 68 seconds.

$Rightarrow$ Words that can be read in 1 second is given by $dfrac{300}{68}$.

Words that can be read in 1 minute (60 seconds) is given by $dfrac{300}{68}times 60=264.7$

Therefore, a person can read around 265 words per minute of the given book.

$bullet$ Given that it takes 68 seconds to read a page, then number of pages that can be read in an hour can be found as shown below

$$
1 text{hour}=60times 60 =3600 text{seconds}
$$

$$
text{pages per second} = dfrac{1}{68}
$$

$$
text{pages in 3600 seconds} = dfrac{1}{68}times 3600=52.94
$$

Therefore, one can read around 53 pages of the book in an hour.

Result
2 of 2
A person can read around 265 words per minute of the given book.

One can read around 53 pages of the book in an hour.

Exercise 124
Result
1 of 1
Possible answer: Most likely, you will feel confident about questions that are already familiar from previous courses like evaluating expressions and solving the Diamond Problems. You may find the lessons in this chapter to be hard (or simply tedious) since it may be your first time answering such problems but with practice and in time, you will eventually find them easy to solve.
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