Solve for: c-9 >-13

Expression: $-5{x}^{2}+250=0$

Divide both sides of the equation by $-5$

${x}^{2}-50=0$

Move the constant to the right-hand side and change its sign

${x}^{2}=50$

Take the square root of both sides of the equation and remember to use both positive and negative roots

$x=5\sqrt{ 2 }$

Write the solutions, one with a $+$ sign and one with a $-$ sign

$\begin{array} { l }x=-5\sqrt{ 2 },\\x=5\sqrt{ 2 }\end{array}$

The equation has $2$ solutions

$\begin{align*}&\begin{array} { l }x_1=-5\sqrt{ 2 },& x_2=5\sqrt{ 2 }\end{array} \\&\begin{array} { l }x_1\approx-7.07107,& x_2\approx7.07107\end{array}\end{align*}$