a. USE FOIL
* first term squared, plus of minus, double the product, plus the last term squared
^ A mathematical hymn which my math teacher taught me.
So:
a. x^2 - 2x +2x - 4
This can simplify to
x^2 + 4
b. y^2 + 2y - 4y - 8
This can simplify to
y^2 - 2y - 8
