(x+15)^2=81

2 min read Jun 16, 2024
(x+15)^2=81

Solving the Equation (x+15)² = 81

This article will guide you through the process of solving the equation (x+15)² = 81. We will use the properties of square roots and basic algebraic manipulation to find the solution(s).

Understanding the Equation

The equation represents a quadratic equation in the form of (x + a)² = b, where 'a' and 'b' are constants. To solve for 'x', we need to isolate it by undoing the operations performed on it.

Solving for x

  1. Take the square root of both sides:
    Since the left side of the equation is squared, we can eliminate the square by taking the square root of both sides: √[(x+15)²] = ±√81

  2. Simplify: The square root of (x+15)² is (x+15), and the square root of 81 is 9. Remember that taking the square root results in both positive and negative values. x + 15 = ±9

  3. Solve for x: We now have two separate equations:

    • x + 15 = 9
    • x + 15 = -9

    Solving for 'x' in each equation:

    • x = 9 - 15 = -6
    • x = -9 - 15 = -24

Solution

Therefore, the solutions to the equation (x+15)² = 81 are x = -6 and x = -24.

Verification

We can verify our solutions by substituting them back into the original equation:

  • For x = -6: (-6 + 15)² = 9² = 81 (True)
  • For x = -24: (-24 + 15)² = (-9)² = 81 (True)

This confirms that both solutions are valid.

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