Answer
When x = 12, y = 180
Step-by-step explanation
We are told that y varies directly as x, which can be written as
y ∝ x
Introducing the constant of variation, k, we have
y ∝ x
y = kx
We can then solve for k knowing that
y = 90 when x = 6
y = kx
90 = (k) (6)
90 = 6k
Divide both sides by 6
(90/6) = (6k/6)
15 = k
k = 15
We can then write the relationship between y and x as
y = kx
y = 15x
when x = 12, y = ?
y = 15x
y = 15 (12) = 180
Hope this Helps!!!