$$a^{2}x-4a=2a^{2}+4x$$
$\left\{\begin{matrix}x=\frac{2a}{a-2}\text{, }&a\neq 2\\x\in \mathrm{C}\text{, }&a=-2\end{matrix}\right.$
$\left\{\begin{matrix}x=\frac{2a}{a-2}\text{, }&a\neq 2\\x\in \mathrm{R}\text{, }&a=-2\end{matrix}\right.$
$\left\{\begin{matrix}\\a=-2\text{, }&\text{unconditionally}\\a=\frac{2x}{x-2}\text{, }&x\neq 2\end{matrix}\right.$
