(x-2)^2-9=0

3 min read Jun 17, 2024
(x-2)^2-9=0

Solving the Quadratic Equation: (x-2)^2 - 9 = 0

This article will guide you through the steps to solve the quadratic equation (x-2)^2 - 9 = 0.

Understanding the Equation

The equation (x-2)^2 - 9 = 0 is a quadratic equation in standard form. It can be rewritten as:

x^2 - 4x - 5 = 0

This equation represents a parabola, and solving it means finding the x-values where the parabola intersects the x-axis.

Methods of Solving

There are several methods to solve quadratic equations, including:

  1. Factoring:

    • Factor the quadratic expression: (x - 5)(x + 1) = 0
    • Set each factor equal to zero:
      • x - 5 = 0 => x = 5
      • x + 1 = 0 => x = -1
  2. Quadratic Formula:

    • The quadratic formula provides the solutions for any quadratic equation in the form ax^2 + bx + c = 0:

    x = (-b ± √(b^2 - 4ac)) / 2a

    • In our case, a = 1, b = -4, and c = -5. Substitute these values into the quadratic formula:

    x = (4 ± √((-4)^2 - 4 * 1 * -5)) / (2 * 1)

    x = (4 ± √(36)) / 2

    x = (4 ± 6) / 2

    • This gives us two solutions:

      • x = (4 + 6) / 2 = 5
      • x = (4 - 6) / 2 = -1
  3. Completing the Square:

    • Move the constant term to the right side: (x - 2)^2 = 9
    • Take the square root of both sides: x - 2 = ±3
    • Solve for x:
      • x = 2 + 3 = 5
      • x = 2 - 3 = -1

Solutions

Regardless of the method used, the solutions to the equation (x-2)^2 - 9 = 0 are:

x = 5 and x = -1

Conclusion

We have successfully solved the quadratic equation (x-2)^2 - 9 = 0 using three different methods. All methods lead to the same solutions: x = 5 and x = -1. These solutions represent the x-intercepts of the parabola represented by the equation.

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