Grade 8 Quarter 3 Test

Describe each association: positive linear, negative linear, nonlinear, or no association.

1. 1
   Association: 
2. 2
   Association: 

Use the line of best fit to answer each question.

1. 3
   The line of best fit for hours studied ($x$) and test score ($y$) is $y=1.9x+30$. Predict $y$ when $x=14$.

Find the slope (rate of change) of each table.

1. 4
   $\begin{array}{ccccc}x& 1& 3& 5& 7\\ y& 3& 5& 7& 9\end{array}$ 
2. 5
   $\begin{array}{ccccc}x& 0& 3& 4& 5\\ y& 0& 15& 20& 25\end{array}$ 

Find the slope and the y-intercept of each line.

1. 6
   $y=x+6$
2. 7
   $y=-1+\frac{3}{4}x$
3. 8
   $y=-\frac{3}{4}x+3$
4. 9
   $y=-\frac{3}{4}x+12$

Write an equation in slope-intercept form for each line.

1. 10
   Equation: 
2. 11
   Equation: 

Is the ordered pair a solution of the equation? Write yes or no.

1. 12
   $(3,14)$; $y=4x-1$ 
2. 13
   $(-4,20)$; $y=-5x$ 

Find the slope and y-intercept, or write an equation in slope-intercept form.

1. 14
   $y=7-\frac{2}{3}x$
2. 15
   slope $\frac{3}{4}$, through $(8,9)$

Write function or not a function.

1. 16
   $\{(6,9),(1,-5),(4,0),(-1,0)\}$ 

Evaluate each function.

1. 17
   $h(x)=-9x-6$; $h(6)=$ 
2. 18
   $g(x)=\frac{3}{2}x+1$; $g(-8)=$ 
3. 19
   $h(x)=\frac{3}{2}x+2$; $h(0)=$ 
4. 20
   $g(x)=2x^2+x+4$; $g(5)=$ 

Complete each table.

1. 21
   $y=6x-10$ $\begin{array}{cccccc}x& -2& 0& 3& 6& 8\\ y& & & & 26& 38\end{array}$
2. 22
   $y=5x-5$ $\begin{array}{cccccc}x& 1& 2& 5& 7& 8\\ y& & & & 30& 35\end{array}$
3. 23
   $y=-4x-3$ $\begin{array}{cccccc}x& 1& 3& 4& 6& 9\\ y& & -15& & & -39\end{array}$
4. 24
   $y=\frac{5}{2}x+7$ $\begin{array}{cccccc}x& -2& 2& 6& 8& 12\\ y& 2& & & 27& \end{array}$

Write a linear function y = mx + b for each table.

1. 25
   $\begin{array}{ccccc}x& 1& 3& 4& 7\\ y& 2& 4& 5& 8\end{array}$
2. 26
   $\begin{array}{ccccc}x& 5& 20& 35& 40\\ y& -5& -8& -11& -12\end{array}$

Write a linear function for each situation.

1. 27
   A candle is $26$ cm tall and burns $2$ cm each hour. Write its height $y$ after $x$ hours.

Write linear or nonlinear.

1. 28
   $y=\frac{5}{2}x+6$ 
2. 29
   $\begin{array}{ccccc}x& 0& 3& 5& 7\\ y& 2& 17& 27& 37\end{array}$ 

Write the domain and range of each relation.

1. 30
   $\{(-2,3),(-6,1),(6,-3),(-3,-1),(-6,0),(-5,2)\}$