Question

y varies directly as the square of x. When x=3, y= 54. Find y when x=8.

Answer 1

y=kx
Variation equation

54=3k

k=18

So plugging that in

y=(18)(8)

y=144

Answer 2

thank you

Answer 3

\[y=kx ^{2}\]

Answer 4

My bad, @kropot72 got me beat

Answer 5

\[y=kx ^{2}\]
\[54=k(3)^{2}\]
\[k=\frac{54}{3^{2}}=6\]
When x = 8
\[y=6\times (8)^{2}\]

Answer 6

\[54=k(3^2)\]
\[6=k\]
\[y=6*(8^2)\]
384