1. Suppose y varies directly with x. Write a direct variation equation that relates x and y.

Question

y= 7 1/2 when x=3

a. y= 3/2 x
b. y= 2/3 x
c. y= 5/2 x
d. y= 2/5 x

2. Suppose y varies directly with x. Write a direct variation equation that relates x and y.

y=10.4 when x=4

a. y= 3.4 x
b. y= 3.8 x
c. y= 3.2 x
d. y= 2.6 x

Answer 1

y = k x
7.5 = k (3)

k = 7.5/3 = 2.5 = 5/2 (c)

10.4 = k (4)
k = 10.4 /4 = 2.6 x