Consider the equation:
[tex]\[ -2x = x^2 - 6 \][/tex]

1. Rewrite the equation by completing the square.

Your equation should look like [tex]\((x+c)^2=d\)[/tex] or [tex]\((x-c)^2=d\)[/tex].
[tex]\[ (x+1)^2=7 \][/tex]

2. What are the solutions to the equation?

Choose one answer:
A. [tex]\( x = 1 \pm \sqrt{7} \)[/tex]
B. [tex]\( x = -1 \pm \sqrt{7} \)[/tex]
C. [tex]\( x = 1 \pm 7 \)[/tex]
D. [tex]\( x = -1 \pm 7 \)[/tex]



Answer :

Sure, let's go through the steps to solve the equation [tex]\(-2x = x^2 - 6\)[/tex] by completing the square.

1. Rewrite the equation in standard quadratic form:
[tex]\[ x^2 + 2x - 6 = 0 \][/tex]

2. Complete the square:
- To complete the square, we need to convert the quadratic equation into the form [tex]\((x + c)^2 = d\)[/tex].
- Our quadratic term is [tex]\(x^2\)[/tex] and the linear term is [tex]\(2x\)[/tex].
- Take half of the coefficient of [tex]\(x\)[/tex] (which is 2), and square it.
[tex]\[ \left(\frac{2}{2}\right)^2 = 1 \][/tex]

3. Rewrite the equation by adding and subtracting this square inside the equation:
[tex]\[ x^2 + 2x + 1 - 1 - 6 = 0 \][/tex]
[tex]\[ (x + 1)^2 - 7 = 0 \][/tex]

4. Rearrange to isolate the square term:
[tex]\[ (x + 1)^2 = 7 \][/tex]

5. Solve for [tex]\(x\)[/tex] by taking the square root on both sides:
[tex]\[ x + 1 = \pm \sqrt{7} \][/tex]
- This gives us two solutions:
[tex]\[ x + 1 = \sqrt{7} \quad \text{or} \quad x + 1 = -\sqrt{7} \][/tex]

6. Isolate [tex]\(x\)[/tex] by subtracting 1 from both sides:
[tex]\[ x = -1 + \sqrt{7} \quad \text{or} \quad x = -1 - \sqrt{7} \][/tex]

Therefore, the solutions to the equation are:

(B) [tex]\(x = -1 \pm \sqrt{7}\)[/tex]

These steps demonstrate how to solve the quadratic equation by completing the square, leading to the solution [tex]\(x = -1 \pm \sqrt{7}\)[/tex].