1. **Problem statement:** Factor the expression given (assuming a general expression since none was specified). 2. **Formula and rules:** To factor an algebraic expression, look for common factors, use special products formulas like difference of squares, perfect square trinomials, or factor by grouping. 3. **Example:** Suppose the expression is $x^2 - 9$. 4. **Step-by-step factorization:** - Recognize this as a difference of squares: $a^2 - b^2 = (a - b)(a + b)$. - Here, $a = x$ and $b = 3$. - So, $x^2 - 9 = (x - 3)(x + 3)$. 5. **Explanation:** The difference of squares formula allows us to rewrite the expression as a product of two binomials, which is the factored form. 6. **Final answer:** The factored form of $x^2 - 9$ is $$(x - 3)(x + 3)$$.