Question

How do you solve `x^2+2x-8=0` using completing the square?

Answer 1

Ifound:
`x_1=2`
`x_2=-4`

Explanation:

Take `-8` to the right:
`x^2+2x=8`
Add and subtract `1`:
`x^2+2x+1-1=`
`x^2+2x+1=8+1`
`(x+1)^2=9`
Root square both sides:
`x+1=+-sqrt(9)`
`x+1=+-3`
`x=-1+-3`
`x_1=2`
`x_2=-4`