$$\frac{x-a-b}{c}+\frac{x-b-c}{a}+\frac{x-c-a}{b}=3$$
$\left\{\begin{matrix}a=x-b-c\text{, }&x\neq b+c\text{ and }b\neq 0\text{ and }c\neq 0\\a=-\frac{bc}{b+c}\text{, }&c\neq 0\text{ and }b\neq 0\text{ and }b\neq -c\end{matrix}\right.$
$\left\{\begin{matrix}b=x-a-c\text{, }&x\neq a+c\text{ and }a\neq 0\text{ and }c\neq 0\\b=-\frac{ac}{a+c}\text{, }&c\neq 0\text{ and }a\neq 0\text{ and }a\neq -c\end{matrix}\right.$
