Observe that is the common factor. So

Observe that is the common factor. So2.

Observe that is the common factor. So3.

This one is slightly more complicated. First observe that .4.

Now, . So now we are left with , which can be factored using the difference of squares formula.

This is similar to #4. Observe that .5.

Now, . So now we are left with , which can be factored using the difference of squares formula.

Does this make sense? Can you try these problems now?