Question

Use the completing the square to solve x^2+6x=12.

Answer 1

x = -3 ±
`√(21)`

Explanation:

`x^2+6x=12`

`((b)/(2) )^(2)` = 9

`x^2+6x + 9 =12 + 9`

`(x+3)^(2) =21`

x + 3 =
`√(21)`

x = -3 ±
`√(21)`

Answer 2

x= -3 ±
`√(21)`

Explanation:

`x^(2)`+6x=12

We add 9 [
`(6/2)^(2)`] to both sides to complete the square as
`x^(2)`+6x+9 =
`(x+3)^(2)`.

`(x+3)^(2)`=21

Now we take the square root of both sides:

x+3=±
`√(21)`

x= -3 ±
`√(21)`