Answer:
x = 2 and x = -4
Step-by-step explanation:
This can be solved by factoring tho if you insist to solve this by completing the squares then the solution would be:
x^2 + 2x = 8
> x^2 + 2x + 1 = 8 + 1
> (x+1)^2 = 9
> x+1 = +-3
> x = -1+-3
x = 2 ; x = -4
