Solution
[tex]\begin{gathered} x^2+2x-16=0 \\ \\ \text{ using quadratic formula} \\ \\ x=\frac{-b\pm\sqrt{b^2-4ac}}{2a} \\ a=1,b=2,c=-16 \\ \\ \Rightarrow x=\frac{-2\pm\sqrt{2^2-4(1)(-16)}}{2(1)} \\ \\ \Rightarrow x=\frac{-2\pm\sqrt{4+64}}{2} \\ \\ \Rightarrow x=-1-\sqrt{17} \\ \\ \Rightarrow x=-1+\sqrt{17} \\ \\ \text{ since }x>0 \\ \\ \text{ Therefore the value of }x=-1+\sqrt{17} \end{gathered}[/tex]
