GT
\(\Leftrightarrow\dfrac{x}{\dfrac{1}{2}}=\dfrac{y}{\dfrac{1}{3}}=\dfrac{z}{\dfrac{1}{4}}=\dfrac{2z}{\dfrac{1}{2}}=\dfrac{x+y-2z}{\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{1}{2}}=\dfrac{-8}{\dfrac{1}{3}}=-24\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=-24.\dfrac{1}{2}=-12\\y=-24.\dfrac{1}{3}=-8\\z=-24.\dfrac{1}{4}=-6\end{matrix}\right.\)