$$px+n=p$$
$\left\{\begin{matrix}p=-\frac{n}{x-1}\text{, }&x\neq 1\\p\in \mathrm{C}\text{, }&n=0\text{ and }x=1\end{matrix}\right.$
$\left\{\begin{matrix}p=-\frac{n}{x-1}\text{, }&x\neq 1\\p\in \mathrm{R}\text{, }&n=0\text{ and }x=1\end{matrix}\right.$
$n=p\left(1-x\right)$