Let's learn how to factorize the expression X² - 81 step by step!
- Understand the Expression: The expression is X squared minus 81. It looks like this: X² - 81.
- Recognize the Type of Expression: This is a difference of squares because it looks like a² - b². Here, a is X (since X² means X times X), and b is 9 (because 9² = 81).
- Recall the Difference of Squares Formula: a² - b² = (a + b)(a - b).
- Apply the Formula: Substitute a = X and b = 9 into the formula:
(X + 9)(X - 9). - Final Factorization: So, X² - 81 = (X + 9)(X - 9).
Summary: To factorize X² - 81, recognize it as a difference of squares and use the formula to get (X + 9)(X - 9).