Answer
The solutions are 2 and -4.
Work Step by Step
$x^{2}$+2x-8=0
$x^{2}$+4x-2x-8=0
x(x+4)-2(x+4)=0
(x-2)(x+4)=0
x-2=0 or x+4=0
x-2+2=0+2 or x+4-4=0-4
x=2 or x=-4
The solutions are 2 and -4.
Check
Let x=2
$x^{2}$+2x-8=0
$2^{2}$ +2*2-8=0
4+4-8=0
8-8=0
0=0
Let x=-4
$x^{2}$+2x-63=0
$(-4)^{2}$ +2(-4)-8=0
16-8-8=0
0=0
