How do you solve x² + 8x + 5 = 0 using the completing the square method?

To solve the quadratic equation x² + 8x + 5 = 0 by completing the square, follow these steps:

  1. Start with the original equation:
  2. x² + 8x + 5 = 0

  3. Move the constant to the other side of the equation:
  4. x² + 8x = -5

  5. To complete the square, take the coefficient of x (which is 8), divide it by 2, and square it:
  6. (8 / 2)² = 4² = 16

  7. Add this square to both sides of the equation:
  8. x² + 8x + 16 = -5 + 16

    This simplifies to:

    x² + 8x + 16 = 11

Now, the left side can be factored as a perfect square:

(x + 4)² = 11

  1. Take the square root of both sides:
  2. x + 4 = ±√11

  3. Now, solve for x by isolating the variable:
  4. x = -4 ± √11

Thus, the solutions are:

x = -4 + √11 and x = -4 – √11.

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