$\left\{\begin{matrix}a=-\frac{b\left(y-1\right)}{x}\text{, }&x\neq 0\\a\in \mathrm{C}\text{, }&\left(b=0\text{ or }y=1\right)\text{ and }x=0\end{matrix}\right.$

$\left\{\begin{matrix}b=-\frac{ax}{y-1}\text{, }&y\neq 1\\b\in \mathrm{C}\text{, }&\left(a=0\text{ or }x=0\right)\text{ and }y=1\end{matrix}\right.$

$\left\{\begin{matrix}a=-\frac{b\left(y-1\right)}{x}\text{, }&x\neq 0\\a\in \mathrm{R}\text{, }&\left(b=0\text{ or }y=1\right)\text{ and }x=0\end{matrix}\right.$

$\left\{\begin{matrix}b=-\frac{ax}{y-1}\text{, }&y\neq 1\\b\in \mathrm{R}\text{, }&\left(a=0\text{ or }x=0\right)\text{ and }y=1\end{matrix}\right.$