Answer:
[tex]x_{1}=-1+\sqrt{17},\:x_{2}=-1-\sqrt{17}[/tex]
Step-by-step explanation:
Quadratic Equation Given:
[tex]x^2+2x-16=0[/tex]
[tex]x^2 + 2x=16[/tex]
[tex]$c=\left( \frac{b}{2} \right)^2 $[/tex]
[tex]x^2 + 2x+1=16+1[/tex]
[tex](x+1)^2=17\\[/tex]
[tex]x+1=\pm \sqrt{17} \\[/tex]
[tex]x=-1 \pm \sqrt{17} \\[/tex]
[tex]x_{1}=-1+\sqrt{17},\:x_{2}=-1-\sqrt{17}[/tex]