Algebra Intermediate - Factoring Difference of Squares

First off, when factoring differences of squares you will be working with two binomial factors and then you will be using what is called the FOIL system. You more than likely learned the FOIL system in pre-algebra but as a quick refresher, the FOIL system refers to multiplying two factors that are surrounded by parentheses.

You multiply the first term in each factor as your first step, then the first term in the first factor (which is also considered an “outer” term) with the “outer” term (or second term) in the second factor. The third step is to multiply the two inner terms, (i.e., the second term of the first factor and the first term of the second factor) and, finally, you multiply the last two terms of each factor. Let’s look at the example below.