Question

Factor 9b2 - 4.

Answer 1

(3b-2)(3b+2)

Answer 2

this can be written as

(3b)^2 - (2)^2

Answer 3

a^2 - b^2 = (a-b) (a+b)

Use this ^^

Answer 4

This is in the form of:
a^2-b^2 = (a-b)(a+b)
where a=3b, and b=2