Which equation shows [tex]\(x^2 + 6x - 6 = 0\)[/tex] rewritten by completing the square?

A. [tex]\((x+3)^2 = 15\)[/tex]

B. [tex]\((x+3)^2 = 9\)[/tex]

C. [tex]\((x+3)^2 = 6\)[/tex]

D. [tex]\((x+3)^2 = 54\)[/tex]



Answer :

To solve the given quadratic equation [tex]\( x^2 + 6x - 6 = 0 \)[/tex] by completing the square, follow these detailed steps:

1. Move the constant term to the right side of the equation:

[tex]\[ x^2 + 6x - 6 = 0 \][/tex]

[tex]\[ x^2 + 6x = 6 \][/tex]

2. Complete the square:

To complete the square, you need to take the coefficient of [tex]\( x \)[/tex] (which is 6), divide it by 2, and then square the result.

[tex]\[ \left( \frac{6}{2} \right)^2 = 3^2 = 9 \][/tex]

Add and subtract this square (9) within the left-hand side of the equation:

[tex]\[ x^2 + 6x + 9 - 9 = 6 \][/tex]

[tex]\[ (x + 3)^2 - 9 = 6 \][/tex]

3. Move the -9 term to the right side to complete the square:

[tex]\[ (x + 3)^2 - 9 = 6 \][/tex]

[tex]\[ (x + 3)^2 = 6 + 9 \][/tex]

[tex]\[ (x + 3)^2 = 15 \][/tex]

Thus, the equation [tex]\( x^2 + 6x - 6 = 0 \)[/tex] rewritten by completing the square is:

[tex]\[ (x + 3)^2 = 15 \][/tex]

So, the correct answer is:

A. [tex]\((x+3)^2=15\)[/tex]