If x varies directly as y and x=12 when y=27 what is x when y=3?

Answer 1

First find a using y = ax and the given info that x=12 when y=27

y = ax

27 = a(12)

a = 27/12 = 2 1/4

Since y = 2 1/4x we can use this and y=3 to find x

y = 2 1/4x

3 = 2 1/4x

3/(2 1/4) = x

1 1/3 = x