Question

State the factoring rule for difference of two squares a2-b2

Answer 1

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

The order of the factors does not matter.

So (a-b)(a+b) is the same as (a+b)(a-b)

This is known as the difference of squares factoring rule.

You can FOIL out (a-b)(a+b) and you'd get a^2+ab-ab-b^2. Note how the ab terms cancel leaving us with a^2-b^2. This confirms we have the correct factorization.