\(\dfrac{6}{11}x=\dfrac{9}{2}y=\dfrac{18}{5}z\)
\(\Leftrightarrow\dfrac{x}{\dfrac{11}{6}}=\dfrac{y}{\dfrac{2}{9}}=\dfrac{z}{\dfrac{5}{18}}\)
Áp dụng tính chất dãy tỉ số bằng nhau ta có:
\(\dfrac{x}{\dfrac{11}{6}}=\dfrac{y}{\dfrac{2}{9}}=\dfrac{z}{\dfrac{5}{18}}=\dfrac{x+y+z}{\dfrac{11}{6}+\dfrac{2}{9}+\dfrac{5}{18}}=\dfrac{-196}{\dfrac{42}{18}}=\dfrac{-98}{\dfrac{21}{18}}=\dfrac{-588}{7}\)
(thấy lẻ,nếu đề ko sai thì làm tiếp)
\(\dfrac{3x-2y}{4}=\dfrac{2z-4x}{3}=\dfrac{4y-3z}{2}\)
\(\Rightarrow\dfrac{12x-8y}{16}=\dfrac{6z-12x}{9}=\dfrac{8y-6z}{4}\)
Áp dụng tính chất dãy tỉ số bằng nhau ta có:
\(\dfrac{12x-8y}{16}=\dfrac{6z-12x}{9}=\dfrac{8y-6z}{4}\)
\(=\dfrac{12x-8y+6z-12x+8y-6z}{16+9+4}=0\)
\(\Rightarrow\left\{{}\begin{matrix}3x=2y\\2z=4x\\4y=3z\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{x}{2}=\dfrac{y}{3}\\\dfrac{x}{2}=\dfrac{z}{4}\\\dfrac{y}{3}=\dfrac{z}{4}\end{matrix}\right.\)
\(\Leftrightarrow\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{4}\)
Áp dụng tính chất dãy tỉ số bằng nhau ta có:
\(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{4}=\dfrac{x+y-z}{2+3-4}=\dfrac{-10}{1}=-10\)
\(\Rightarrow\left\{{}\begin{matrix}x=-10.2=-20\\y=-10.3=-30\\z=-10.4=-40\end{matrix}\right.\)
Vậy......
