$\left\{\begin{matrix}m=-\frac{y-z}{x}\text{, }&x\neq 0\\m\in \mathrm{C}\text{, }&z=y\text{ and }x=0\end{matrix}\right.$

$\left\{\begin{matrix}x=-\frac{y-z}{m}\text{, }&m\neq 0\\x\in \mathrm{C}\text{, }&z=y\text{ and }m=0\end{matrix}\right.$

$\left\{\begin{matrix}m=-\frac{y-z}{x}\text{, }&x\neq 0\\m\in \mathrm{R}\text{, }&z=y\text{ and }x=0\end{matrix}\right.$

$\left\{\begin{matrix}x=-\frac{y-z}{m}\text{, }&m\neq 0\\x\in \mathrm{R}\text{, }&z=y\text{ and }m=0\end{matrix}\right.$