The equation a² - b² = (a + b)(a - b) is known as the difference of squares formula. It shows how the difference between two squared numbers, a² and b² , can be factored into the product of two binomials: (a + b) and (a - b) . This relationship is useful in algebra for simplifying expressions and solving equations. In practical terms, if you have two numbers, say a and b, you can quickly find the difference of their squares by using this formula. For example, if a = 5 and b = 3 , then 5² - 3² = (5 + 3)(5 - 3) = 8 \times 2 = 16 , confirming the equation's validity.