1. if f(x) varies directly with x, and f(x) = 12 when x = 8, write the direct linear variation equation.

a. f(x)=8x
b. f(x)=12x
c. f(x)=2/3x
d. f(x)=3/2x

2.which does not show a direct variation between x and y?

a. y=5x
b. y=6/x
c. y=0.7x
d. y=x/9

3.find the constant of variation for the relationship shown in the following table:

x 1 2 3 4
y 3 6 9 12