Factor completely. 5x2 - 45

5 (x + 3) (x - 3)

Step-by-step explanation:

Both terms in this expression have 5 in common---they both have a factor of 5. Therefore you can factor out a 5 like this:

5 (x^2 - 9)

This can be even further factored. Find what two numbers multiply to - 9 but add to 0. - 3 and 3 are numbers that work. You can make x^2 - 9 become (x + 3) and (x - 3).

5 (x + 3) (x - 3) is the final answer simplified completely.

5 (x-3) (x+3)