Pull the out from both terms:

The odds are you did something wrong with your simplification. Since you didn't show us your work, I can only speculate.

You can factor a :

Difference of what squares? I don't see any.

You factored correctly, now simplify:

You can factor a from each term:

Now simplify.

Remember the parenthesis!!

Again you can factor more than you did: you can take a out of both terms.

If your terms have more than one thing in common you can factor them all out. If you like, for simplicity and until you get used to the idea, you can take them out one by one. No harm there and it will make checking your work easier. With this last one your only flaw (aside from the parenthesis(!)) was that you didn't go far enough. Both terms still had something you could factor out.

-Dan