How would I solve this by completing the square? x^2+ 8x

Wait a sec

You could use mathpapa.com

I'll give that a try.

Eric, it didn't show me the steps to get the answer.

x^2 + 8x - 2
8/2 = 4, and 4^2 = 16, so add and subtract 16
x^2 + 8x + 16 - 2 - 16
(x+4)^2 - 18

Hmmm, a relatively hard question but I can solve it
x^2+8x=2,
If b=8, then we need to add (b/2)^2=16,
So x^2+8x+16=18,
(X+4)^2=+- sqrt18,
x=-4(3sqrt2)
P.S sorry about the late response.

Thanks Eric!