suppose y varies directly with x. write a direct variation equation that relates x and y. then find the value of y when x=12. y=3 when x=2

y ∝ x

⇒ y = kx

When x = 12 and y = 3, substitute into the formula above

3 = k x 12

k = 1/4

substitute k = 1/4 into the formula

y = x/4 which is the equation that relates x and y

Ti find y when x = 2

⇒ y = 2/4

y = 1/2