Question

Factor 4x^2 - 36 completely.

Answer 1

Factor: 4x^2-36

4x^2-36
=4(x+3)(x-3)
4(x+3) (x-3) 

Answer 2

You're answer is C because you can do the F.O.I.L. and then multiply it by 4. like this:

   4(x+3)(x-3)
4(x^2+3x-3x-9)
4x^2-36.

F.O.I.L is:
 First Term
Outer Term
Iner Term
Last Term.