N00b

I've been having some problems with these, if someone could help that's be nice.

Perform the indicated operations and simplify.

x^2 - x - 6 x^2 - 3x - 4

x^2 + 4x + 3 * x^2 - 4x + 3

(Note: This was originally a division problem but I flipped the last fraction to make it multiplication as I think your suppose to, that and I didn't know how to type the division sign.)

Find the lowest common denominator:

5a - 15, 10a - 30

Solve the equation.

2 + x - 1 = x^2 - 1

x + 2 x + 3 x^2 + 5x + 6

Perform the indicated operations and simplify.