Please help me understand what I'm missing here. I'm finding the marginal distribution of X, and my answer (worked out in blue) does not match the real solution (highlighted )

First, let's find the marginal distribution of X. my answer fx(z) = 21x2y' dy . fy (x ) = S 21 x ys dy - 21 ( 12y'dy 21 5 x 2y dy X Real [12 - x5] 21? ANSWER - = x (x1 - 1) = 21 X 2 [4 - 4] = 4. X 2 ( 1 - X4 ) fy ( x ) : * " (1 - x Y )