Solve x2 + 12x = - 11 by completing the square. Which is the solution set of the equation?

{-11, - 1}

{-11, 1}

{11, - 1}

{11, 1}

O

{-11, - 1}

Step-by-step explanation:

x^2 + 12x = - 11

Take the coefficient of x

12

Divide by 2

12/2 = 6

Then square it

6^2 = 36

Add this to both sides

x^2 + 12x+36 = - 11+36

(x+6) ^2 = 25

Take the square root of each side

sqrt ((x+6) ^2) = ± sqrt (25)

x+6 = ± 5

Separate into two equations

x+6 = 5 x+6=-5

Subtract 6 from each side

x+5-6 = 5-6 x+6-6 = - 5-6

x=-1 x=-11