# Chapter 4: Linear Functions and Relations

Q1.

Write an equation of a line in slope-intercept form with the given slope and $\mathit{y}$-intercept. Then graph the equation.

Slope: 2, $\mathit{y}$-intercept: 4

Q1.

Write an equation in slope-intercept form for each graph shown.

Q1.

Graph$y=2x-3$.

Q1.

State whether each sentence is *true* or *false*. If *false* replace the underlined word or number to make a true sentence.

The __y____-intercept__ is the *y*-coordinate of the point where the graph crosses the $y$-axis .

Q1.

A shipping company charges $\$8.50$ to ship packages that weigh up to 1 pound and role="math" localid="1647336641330" $\$7.25$for each additional pound. Which of the following piecewise-defined functions represents the cost *C* of shipping a package that weighs *p* pounds?

A $C\left(p\right)=\left\{\begin{array}{l}8.50\text{if}p\le 1\\ 8.50+7.25p\text{if}p>1\end{array}\right.$

B $C\left(p\right)=\left\{\begin{array}{l}7.25\text{if}p\le 1\\ 7.25+8.50p\text{if}p>1\end{array}\right.$

C$C\left(p\right)=\left\{\begin{array}{l}\text{8.50if}p\le 1\\ 8.50p+7.25\left(p-1\right)\text{if}p>1\end{array}\right.$

D$C\left(p\right)=\left\{\begin{array}{l}\text{8.50if}p\le 1\\ 8.50+7.25\left(p-1\right)\text{if}p>1\end{array}\right.$

Q1.

Evaluate $3{a}^{2}-2ab+c$for the values given.

$a=2,b=1,c=5$

Q10.

Graph each equation.

$\mathbf{15}\mathit{y}\mathbf{=}\mathbf{3}$

Q10.

The table shows the relationship between years of experience and teacher salary.

Years Experience | 1 | 5 | 10 | 15 | 20 |

Salary (thousands of dollars) | 28 | 31 | 42 | 49 | 64 |

a. Write an equation for the best-fit line.

b. Find the correlation coefficient and explain what it tells us about the relationship between experience and salary.

Q10.

Write an equation of a line in slope-intercept form with the given slope and $y$-intercept. Then graph the equation.

Slope: 3, $y$-intercept: 5

Q10.

Write an equation of the line with the given conditions.

$\left(2,1\right)$, slope 0.