$$R_{Z}=\frac{5X(\frac{km}{n})}{\frac{m}{5}}$$
$\left\{\begin{matrix}X=\frac{R_{Z}n}{25k}\text{, }&k\neq 0\text{ and }n\neq 0\text{ and }m\neq 0\\X\in \mathrm{R}\text{, }&R_{Z}=0\text{ and }k=0\text{ and }n\neq 0\text{ and }m\neq 0\end{matrix}\right.$
$R_{Z}=\frac{25Xk}{n}$
$n\neq 0\text{ and }m\neq 0$
