Y varies directly to x. When y = 16, x = 4. Determine x when y = 36.

x = 9

Step-by-step explanation:

Given y varies directly with x then the equation relating them is

y = kx ← k is the constant of variation

To find k use the given condition when y = 16, x = 4

16 = 4k (divide both sides by 4)

k = 4

y = 4x ← equation of variation

When y = 36, then

36 = 4x (divide both sides by 4)

x = 9

Answer: 9