I don't understand factoring - here are some problewms I am looking to see complete step by step because no matter what I do I am not getting the right answers!!

6x^2y^2 + 12xy^2 + 12y^2

a^2 + 2a - 24

z^3 + 9z^2 +18z

a^4 - ab3

and then for review I am confused on these:

t^8 / t^2

8t^

____

2t^2

I have read the book and gone step by step but something just isn't clicking... I am desperate as I have a test next week and I can't even do my homework!

Thank you in advance to anyone who helps!