If y varies directly with x when y=1/3 and x = 12, find x if y is 4.

x = 144

Step-by-step explanation:

y α x

we introduce a constant 'k' when changing from α to =.

i. e y = kx

y = ⅓ when x = 12

Meaning, ⅓ = k * 12

⅓ = 12k

k = ⅓ : 12

k = 1/36

If y = 4, x = ?

using the equation y = kx

4 = (1/36) x

x = 4 : (1/36)

x = 4 * 36

x = 144