Solve the following quadratic function by completing the square. \[ y=x^{2}+2 x-9 \]

Solve the equation \( x^{2}+2x-9=0 \). Solve the quadratic equation by following steps: - step0: Solve using the quadratic formula: \(x^{2}+2x-9=0\) - step1: Solve using the quadratic formula: \(x=\frac{-2\pm \sqrt{2^{2}-4\left(-9\right)}}{2}\) - step2: Simplify the expression: \(x=\frac{-2\pm \sqrt{40}}{2}\) - step3: Simplify the expression: \(x=\frac{-2\pm 2\sqrt{10}}{2}\) - step4: Separate into possible cases: \(\begin{align}&x=\frac{-2+2\sqrt{10}}{2}\\&x=\frac{-2-2\sqrt{10}}{2}\end{align}\) - step5: Simplify the expression: \(\begin{align}&x=-1+\sqrt{10}\\&x=\frac{-2-2\sqrt{10}}{2}\end{align}\) - step6: Simplify the expression: \(\begin{align}&x=-1+\sqrt{10}\\&x=-1-\sqrt{10}\end{align}\) - step7: Rewrite: \(x_{1}=-1-\sqrt{10},x_{2}=-1+\sqrt{10}\) The solutions to the quadratic function \(y=x^{2}+2x-9\) by completing the square are \(x=-1-\sqrt{10}\) and \(x=-1+\sqrt{10}\).