Answer:
x = 8
Explanation:
Given
y = kx ← k is the constant of variation
To find k use the condition y = 18, x = 4 , then
18 = 4k ( divide both sides by 4 )
4.5 = k
y = 4.5x ← equation of variation
When y = 36, then
36 = 4.5x ( divide both sides by 4.5 )
8 = x