Question

If y varies directly as x^2 and y = 72 when x =3, what is the value of y when x = 6?

Answer 1

288

Explanation:

`y \alpha x {}^(2)`

then

`y = kx {}^(2)`

72=9k

dividing both side by 9

k=72÷9

=8

`y = 8 {x}^(2)`

y=8×6²

y=8×36

y=288