Exam Review (Ch.8)

Which is an example of direct variation?

• $y+1=2x+3$

• $xy=5$

• $2y=5x$

• $y=-8x+5$

y varies directly with x, when x=36, and y=9. What is the equation?

• $y=4x$

• $y=\frac{1}{4}x$

• $y=\frac{4}{x}$

• $y=\frac{.25}{x}$

d varies inversely with f when d=4 and f=16. What is the equation?

• $d=4f$

• $d=64f$

• $d=\frac{4}{f}$

• $d=\frac{64}{f}$

y varies jointly with w and x and inversely with z, when y=300, w=2, x=8, and z=.5

What is the equation?

• $y=37.5wxz$

• $y=\frac{37.5wx}{z}$

• $y=\frac{9.375wx}{z}$

• $y=\frac{18.75wx}{z}$

Write an equation for the graph above.

• $y=\frac{2}{x+3}+2$

• $y=\frac{-2}{x+3}-2$

• $y=\frac{2}{x-3}+2$

• $y=\frac{2}{x-3}-2$

Write an equation for the graph above.

•  $y=\frac{3}{x}-4$  

•  $y=\frac{3}{x-4}$  

•  $y=\frac{-3}{x}-4$  

•  $y=\frac{-3}{x-4}$  

Write an equation for the translations of

 $y=\frac{-9}{x}$  
with asymptotes x=2, and y= -2.

•  $y=\frac{-9}{x-2}+2$  

•  $y=\frac{-9}{x-2}-2$  

•  $y=\frac{-9}{x+2}+2$  

•  $y=\frac{-9}{x+2}-2$  

Simplify

 $\frac{x^2-2x-24}{x^2-36}$  

•  $\frac{x+4}{x+6}$  

•  $\frac{x+4}{x-6}$  

•  $\frac{x+6}{x+4}$  

•  $\frac{x-6}{x+4}$  

Simplify

 $\frac{x^2+5x-36}{x^2-13x+36}$  

• 1

•  $\frac{x+9}{x-9}$  

•  $\frac{x-9}{x+9}$  

• 0

Multiply

 $\frac{x^2}{x+2}\times\frac{x^2-3x-10}{x^2+5x}$  

• 1

•  $\frac{x-5}{x+5}$  

•  $\frac{x+5}{x-5}$  

•  $\frac{x\left(x-5\right)}{x+5}$