Question

Suppose that y varies directly with .x, and y=-8 when x=2.

(a) Write a direct variation equation that relates x and y.
Equation:
(b) Find y when x = 5.
OC

Answer 1

A. y = -4x

B. y = 20

Explanation:

A. y = xk

Where k is constant

Substitute y for -8 and x for 2

-8 = 2k

Divide both sides by 2

-8/2 = 2k/2

-4 = k

k = -4

y = x(-4)

y = -4x

B. y when x = 5

y = 5(-4)

y = 20