This week in math, I have learned the “difference of squares” rule. In a situation like this: , rather than FOILing, you can just use this rule to easily find the product of the expression. always equals . So in a situation where you are given polynomials like this: , you know that it will equal or . You can just use this formula to solve questions rather than going through the whole FOILing process, because you know that the middle part will cancel out.