How can I solve the equation x² + 8x + 3 = 0 using the completing the square method?

To solve the quadratic equation x² + 8x + 3 = 0 using the completing the square method, follow these steps:

  1. Start with the original equation:
    x² + 8x + 3 = 0
  2. Isolate the constant:
    x² + 8x = -3
  3. Complete the square:

    To complete the square, we need to add and subtract the square of half the coefficient of x. The coefficient of x is 8, so:

    Half of 8 is 4, and squaring it gives us:

    (4)² = 16

    Add 16 to both sides of the equation:

    x² + 8x + 16 = -3 + 16
  4. Simplify:
    x² + 8x + 16 = 13
  5. Factor the left side:

    Now the left side can be factored into a perfect square:

    (x + 4)² = 13
  6. Take the square root of both sides:

    Taking the square root gives us:

    x + 4 = ±√13
  7. Isolate x:

    Finally, we isolate x:

    x = -4 ± √13

This results in two potential solutions:

  • x = -4 + √13
  • x = -4 – √13

And that’s how you solve the equation x² + 8x + 3 = 0 using the completing the square method!

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