The Quadratic Formula

$$x=\frac{-<!--\; -\; -->b\pm <!--\; \pm \; -->\sqrt{b^2-<!--\; -\; -->4ac}}{2a}$$

The quadratic formula gives the solutions of $a{x}^2+bx+c=0$ for real numbers $a$, $b$, $c$ with $a\ne <!--\; \ne \; -->0$.