\(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{-x}{x-6}+\dfrac{y}{y+10}=1\\\dfrac{-x-6}{x-6}+\dfrac{4y+10}{y+10}=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}\dfrac{-x+6-6}{x-6}+\dfrac{y+10-10}{y+10}=1\\\dfrac{-x+6-12}{x-6}+\dfrac{4y+40-30}{y+10}=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{-6}{x-6}+\dfrac{-10}{y+10}=1\\\dfrac{-12}{x-6}+\dfrac{-30}{y+10}=-3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}\dfrac{-12}{x-6}+\dfrac{-20}{y+10}=2\\\dfrac{-12}{x-6}+\dfrac{-30}{y+10}=-3\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{10}{y+10}=5\\\dfrac{-6}{x-6}+\dfrac{-10}{y+10}=1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=-8\\x=5\end{matrix}\right.\)
