Solving a Radical Equation in Quadratic Form

$7-\left(\frac{5\pm\sqrt{17}}{2}\right)^2$

$\left(\frac{5\pm\sqrt{17}}{2}\right)^2-7$

$\frac{5+\sqrt{17}}{2}-7$

$\left(\frac{5-\sqrt{17}}{2}\right)^2-7$