The value of y varies directly with x2, and y = 150 when x = 5.

What is the value of y when x=3?

The value of y when x=3 when the value of y varies directly with x^2, and y = 150 when x = 5 is 54. Since the value of y varies directly with x2, then: y = k * x^2, where k is constant. When y = 150 and x = 5, the value of constant is: 150 = k * 5^2. 150 = k * 25. k = 150/25. k = 6. Thus, when x = 3, the value of y will be: y = 6 * 3^2. y = 6 * 9. y = 54.