Question

Factor each of the the following difference of the squares

1. x^2-9

2. 36x^2-81

Answer 1

\[(x-3)(x+3)\]because
\[a^2-b^2=(a+b)(a-b)\]

Answer 2

what about for 36x^2-81

Answer 3

same idea. see if you see that both
\[36x^2\] and \[81\] are "perfect squares" in the form
\[a^2-b^2\]

Answer 4

so would it be (x+6)(x-6)- (9 x 9)?

Answer 5

It would be (6x-9)(6x+9)

Answer 6

thank you!