Question

Solve for x: x2 + 8x = -1

Answer 1

$x^2+8x=-1\\ x^2+8x+16-16=-1\\ (x+4)^2=15\\ x+4=\sqrt{15} \vee x+4=-\sqrt{15}\\ x=-4+\sqrt{15} \vee x=-4-\sqrt{15}$