Solving the Quadratic Equation: (x-5)² - 9 = 0
This article will guide you through the process of solving the quadratic equation (x-5)² - 9 = 0.
Understanding the Equation
The equation (x-5)² - 9 = 0 is a quadratic equation because it has a term with x² in it. Quadratic equations can be solved using several methods, and we will explore two common techniques:
1. Factoring
- Step 1: Expand the square:
(x-5)² expands to (x-5)(x-5) = x² - 10x + 25.
This gives us: x² - 10x + 25 - 9 = 0 - Step 2: Simplify the equation: Combine the constant terms: x² - 10x + 16 = 0
- Step 3: Factor the quadratic expression: The expression factors into (x-8)(x-2) = 0.
- Step 4: Solve for x:
For the product of two factors to equal zero, at least one of the factors must be zero. Therefore, either:
- x - 8 = 0, which means x = 8
- x - 2 = 0, which means x = 2
2. Using the Square Root Property
- Step 1: Isolate the squared term: Add 9 to both sides of the equation: (x-5)² = 9
- Step 2: Take the square root of both sides: √(x-5)² = ±√9
- Step 3: Solve for x:
x - 5 = ±3
- x = 5 + 3 = 8
- x = 5 - 3 = 2
Conclusion
Both methods lead to the same solutions: x = 8 and x = 2. The best method to use depends on your preference and the specific equation. Factoring is generally quicker if the equation can be easily factored, while the square root property is a reliable approach for more complex equations.