These aren't beginning-algebra factoring exercises; they are limits, from calculus.
Please clarify why you are stuck. Are you in calculus, but need a refresher on some aspect of the algebra involved? Or have you never taken calculus, so you didn't know what they meant by the "lim" stuff?
When you reply, please show everything you have tried so far, even if you think it is wrong. Thank you.
Eliz.