I'm kinda stuck with two types of problems given to me. First is about division of algebraic expressions using long division and the other is synthetic division. I'm kinda confused with what i'm supposed to do next. Here are the problems:

Long division:

1. 12x^3-11x^2y-12xy-25y^3 / 3x-5y

2. 9m^3 - 32m^3 + 42m^6 - 15n^2 + 6 - n / 7m^3 + 5n - 3

The first two, I'm stuck since I couldn't find a similar term to subract the product I got.

3. 6xy - 6xz - 2yz + z^2 + y^2 + 9x^2 / 3x + y - z

I got 3x + 2y - z - (-y^2-yz/3x+y-z) though I'm not entirely sure with my answers.

Synthetic Division:

1. x^5-y^5 / x-y

2. (x^2-xy+y2) / (x+y)

3. (x^3 + x^2y+xy^2+y^3) / (x-y)