1. ## Iterated integrals

kinda frustrated with these, how would i go about solving this problem? Thank you.

2. Integrate with respect to y, substitute the terminals then do the same for x.

3. You mean just evaluate it? These are simple polynomials.

$\int 4x^{3} - 9x^{2}y^{2}\;dy\;=\;4x^{3}y - 3x^{2}y^{3} + C$

When working on "dy", just treat 'x' like a constant.