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.