Question

The value of y varies directly with x. If x = 4, then y = 36. Find the value of x when y = 144.

Answer 1

• 16

Explanation:

Direct variation formula: y = kx

Given

• x = 4, y = 36

Finding the coefficient k:

• 36 = 4k
• k = 36/4
• k = 9

So the function is

• y = 9x

Solving for x, when y = 144

• 144 = 9x
• x = 144/9
• x = 16