$\left\{\begin{matrix}C=-\frac{2-5x}{Fx}\text{, }&x\neq 0\text{ and }F\neq 0\\C\in \mathrm{C}\text{, }&x=\frac{2}{5}\text{ and }F=0\end{matrix}\right.$

$\left\{\begin{matrix}F=-\frac{2-5x}{Cx}\text{, }&x\neq 0\text{ and }C\neq 0\\F\in \mathrm{C}\text{, }&x=\frac{2}{5}\text{ and }C=0\end{matrix}\right.$

$\left\{\begin{matrix}C=-\frac{2-5x}{Fx}\text{, }&x\neq 0\text{ and }F\neq 0\\C\in \mathrm{R}\text{, }&x=\frac{2}{5}\text{ and }F=0\end{matrix}\right.$

$\left\{\begin{matrix}F=-\frac{2-5x}{Cx}\text{, }&x\neq 0\text{ and }C\neq 0\\F\in \mathrm{R}\text{, }&x=\frac{2}{5}\text{ and }C=0\end{matrix}\right.$