= a^4 + 9a^2 – 4a^2 + 36 – a + 3

= a^4 + 5a^2 – a + 39

2) ax^3 over a^5y (multiplied by) a^4y^3 over y^2

ax^3 a^4y^3

—— x———-

a^5y y^2

x^3 a^4y

—– x

a^4y

x^3

the correct answer would have been A^4 + 5A^2 – 33

because – (a + 3) becomes -a – 3 and not -a + 3 and because – 4 * 9 = -36 and not +36. those negative signs can get very tricky so be careful and work slowly.

the 2nd problem should be pretty easy i think, i couldn’t really understand the work but we arrived at the same answer. my method would have just been to multiply the numerators with the numerators and the denominators with the denominators to get one fraction. from that one fraction you can just cancel out the A’s and Y’s and end up with X^3.

your 3rd problem, i’m clueless, maybe it’s one of those trick questions or you made a mistake in reproducing the problem for us.