Rewrite the equation by completing the square.

\[x^{2} +7 x +12 = 0\]
\[(x + {}\]

\[)^2 = {}\]

1 answer

To rewrite the equation \(x^{2} + 7x + 12 = 0\) by completing the square, we follow these steps:

  1. Start with the original equation: \[ x^2 + 7x + 12 = 0 \]

  2. Move the constant term to the other side: \[ x^2 + 7x = -12 \]

  3. To complete the square, take the coefficient of \(x\) (which is 7), divide it by 2, and square it: \[ \left(\frac{7}{2}\right)^2 = \frac{49}{4} \]

  4. Add \(\frac{49}{4}\) to both sides of the equation: \[ x^2 + 7x + \frac{49}{4} = -12 + \frac{49}{4} \]

  5. Simplify the right side. First, convert \(-12\) into a fraction with a denominator of 4: \[ -12 = -\frac{48}{4} \] So, \[ -12 + \frac{49}{4} = -\frac{48}{4} + \frac{49}{4} = \frac{1}{4} \]

  6. The left-hand side can be factored since we have completed the square: \[ (x + \frac{7}{2})^2 = \frac{1}{4} \]

Thus, the equation by completing the square is: \[ (x + \frac{7}{2})^2 = \frac{1}{4} \]

So, you can fill in the blanks as follows: \[ \begin{align*} x + \frac{7}{2} \ \frac{1}{4} \end{align*} \]