is a difference of two cubes - consider it written as . Use the formula for difference of two cubes with and .
For the other problem, , out of the first two terms, factor and out of the last two terms factor out -4. This gives:
. Now, both terms have a in common, so factor that out, giving:
. The last step for finishing this one is to factpr , which is a difference of squares.
Hope this helps!