How to Use the Difference of Two Squares Formula

Math students learn many different factoring formulas. The difference of two squares is one of these formulas. Students learn this formula early on in algebra and continue to use it throughout their math career. Follow these steps to learn to use the difference of two squares formula.

Instructions

1. Recognize a square. A square has an exponent of 2. For instance, the number 4 is a square of 2 or 2^2. Look for equations that have two squares subtracted from one another.

2. Note that the special form of the difference of two squares is (x - 1)(x + a) = x^2 - 2^2. That full equation and especially x^2 - 2^2 is seen over and over throughout your math career. Commit it to memory.

3. Learn the terminology for algebra such as monomial, variable, constant and coefficient. A polynomial is composed of 2 or more monomials. For instance, our x^2 - a^2 is a polynomial.

4. Recognize that the difference of two squares is composed of a variable squared, minus another number squared. A few examples of squares include 4 = 2^2, 9 = 3^2, 1 = 1^2 or 144 = 12^2. A square is any number that can go in an exponent-of-two form.

5. Use the difference of two squares, x^2 - a^2, factored out to (x - a)(x + a) to find the zeros or x's of the equation. Find the missing variable since that is what algebra is all about.