To solve the quadratic equation x² + 12x + 49 = 0 by completing the square, follow these steps:
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First, rewrite the equation:
x² + 12x + 49 = 0
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Next, we want to isolate the constant term on one side to focus on completing the square. To do this, we can move the constant (49) to the right side:
x² + 12x = -49
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Now, we need to complete the square on the left side. Take the coefficient of x (which is 12), divide it by 2 (getting 6), and then square it (resulting in 36).
So, we add 36 to both sides of the equation:
x² + 12x + 36 = -49 + 36
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This simplifies to:
x² + 12x + 36 = -13
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Now, we can factor the left side as a perfect square:
(x + 6)² = -13
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Next, we take the square root of both sides, remembering to consider both the positive and negative roots:
x + 6 = ±√(-13)
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We simplify this further, noting that √(-13) can be expressed in terms of imaginary numbers:
x + 6 = ±i√13
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Finally, isolate x by subtracting 6 from both sides:
x = -6 ± i√13
So, the solutions to the equation x² + 12x + 49 = 0 using the method of completing the square are:
- x = -6 + i√13
- x = -6 – i√13