1. Let's start by stating the problem: You want to understand how to apply the difference of squares to simplify a denominator. 2. The difference of squares formula is: $$a^2 - b^2 = (a - b)(a + b)$$. This means if you have an expression like $$x^2 - y^2$$, you can factor it into the product of two binomials. 3. For example, if the denominator is $$x^2 - 9$$, recognize that $$9 = 3^2$$, so it fits the difference of squares pattern. 4. Applying the formula: $$x^2 - 3^2 = (x - 3)(x + 3)$$. 5. This factorization helps simplify expressions by canceling common factors in numerator and denominator if possible. 6. Remember, difference of squares only works when you have a subtraction between two perfect squares. 7. So, whenever you see a denominator like $$a^2 - b^2$$, factor it as $$(a - b)(a + b)$$ to simplify your expression.