Expanding the Expression (2a - 5b - 3)(2a - 5b + 2)
This article will guide you through the process of expanding the expression (2a - 5b - 3)(2a - 5b + 2) using the FOIL method and the distributive property.
Using the FOIL Method
The FOIL method stands for First, Outer, Inner, Last, and it's a helpful mnemonic for multiplying binomials. Let's break down the process:
- First: Multiply the first terms of each binomial: (2a)(2a) = 4a²
- Outer: Multiply the outer terms of each binomial: (2a)(2) = 4a
- Inner: Multiply the inner terms of each binomial: (-5b)(2a) = -10ab
- Last: Multiply the last terms of each binomial: (-5b)(2) = -10b
Now, we have the expanded form: 4a² + 4a - 10ab - 10b - 3(2a - 5b + 2)
Applying the Distributive Property
Next, we need to distribute the -3 to the terms inside the parentheses:
-3(2a - 5b + 2) = -6a + 15b - 6
Combining Like Terms
Finally, we combine the like terms:
4a² + 4a - 10ab - 10b - 6a + 15b - 6 = 4a² - 2a - 10ab + 5b - 6
Final Expanded Expression
Therefore, the expanded form of (2a - 5b - 3)(2a - 5b + 2) is 4a² - 2a - 10ab + 5b - 6.
Conclusion
Expanding expressions like this one is crucial in algebra and other areas of mathematics. By understanding the FOIL method and the distributive property, you can efficiently simplify and manipulate these expressions.