$$x/5=3/7ENTONCESx.7$$
$\left\{\begin{matrix}C=\frac{2}{3OST\left(EN\right)^{2}}\text{, }&N\neq 0\text{ and }E\neq 0\text{ and }S\neq 0\text{ and }O\neq 0\text{ and }T\neq 0\\C\in \mathrm{C}\text{, }&x=0\end{matrix}\right.$
$\left\{\begin{matrix}C=\frac{2}{3OST\left(EN\right)^{2}}\text{, }&N\neq 0\text{ and }E\neq 0\text{ and }S\neq 0\text{ and }O\neq 0\text{ and }T\neq 0\\C\in \mathrm{R}\text{, }&x=0\end{matrix}\right.$
$\left\{\begin{matrix}E=-\frac{\sqrt{6}C^{-0.5}O^{-0.5}S^{-0.5}T^{-0.5}}{3N}\text{; }E=\frac{\sqrt{6}C^{-0.5}O^{-0.5}S^{-0.5}T^{-0.5}}{3N}\text{, }&N\neq 0\text{ and }S\neq 0\text{ and }C\neq 0\text{ and }O\neq 0\text{ and }T\neq 0\\E\in \mathrm{C}\text{, }&x=0\end{matrix}\right.$