Answer:
D
Step-by-step explanation:
[tex]2x^2+16x-8=0[/tex]
Simplify:
[tex]x^2+8x=4[/tex]
Rewrite in the form [tex](x+a)^2=b[/tex]:
[tex]x^2+8x=4[/tex]
Add [tex]4^2[/tex] to both sides:
[tex]x^2+8x+4^2=4+4^2[/tex]
[tex]x^2+8x+4^2=20[/tex]
[tex]\left(x+4\right)^2=20[/tex]
[tex]x+4=\sqrt{20}[/tex] or [tex]x+4=-\sqrt{20}[/tex]
x = -4±[tex]\sqrt{20}[/tex]
x= -4±[tex]2\sqrt{5}[/tex]
