Simplifying the Expression: (2a-5)² + (9-2a)(9+2a)
This article will guide you through simplifying the given algebraic expression: (2a-5)² + (9-2a)(9+2a).
Understanding the Concepts
Before we start simplifying, let's recall some key algebraic concepts:
- Squaring a binomial: (a + b)² = a² + 2ab + b² and (a - b)² = a² - 2ab + b²
- Difference of squares: (a + b)(a - b) = a² - b²
Simplifying the Expression
Let's break down the simplification step-by-step:
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Expand (2a-5)²: Using the formula (a - b)² = a² - 2ab + b², we get: (2a-5)² = (2a)² - 2(2a)(5) + (5)² = 4a² - 20a + 25
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Expand (9-2a)(9+2a): Using the difference of squares formula, we get: (9-2a)(9+2a) = 9² - (2a)² = 81 - 4a²
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Combine the expanded terms: Now we have: (2a-5)² + (9-2a)(9+2a) = 4a² - 20a + 25 + 81 - 4a²
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Simplify by combining like terms: 4a² - 20a + 25 + 81 - 4a² = -20a + 106
Final Result
Therefore, the simplified form of the expression (2a-5)² + (9-2a)(9+2a) is -20a + 106.