Question

If x and y are in direct proportion and y is 6 when x is 9, find y when x is 3.

Answer 1

Answer: y = 2

Explanation:

Direct proportion means that we can write an equation like

(9/6) = (3/y)

we want to isolate y, so multiply both sides by y.

9y/6 = 3

now multiply both sides by 6

9y = 18

y = 2

y = 2 when x is 3