2+6x-x^2

2+6x-x^2   = 0     multiply through by -1 and rearrange

x^2 - 6x  - 2   = 0     this will not factor.......using the on-site solver (and the quadratic formula), we have...

$${{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{\mathtt{6}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{2}} = {\mathtt{0}} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = {\mathtt{3}}{\mathtt{\,-\,}}{\sqrt{{\mathtt{11}}}}\\ {\mathtt{x}} = {\sqrt{{\mathtt{11}}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{3}}\\ \end{array} \right\} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = -{\mathtt{0.316\: \!624\: \!790\: \!355\: \!399\: \!8}}\\ {\mathtt{x}} = {\mathtt{6.316\: \!624\: \!790\: \!355\: \!399\: \!8}}\\ \end{array} \right\}$$