Ta có: \(\dfrac{-5}{x}=\dfrac{-y}{8}=\dfrac{-18}{72}\)
\(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{-5}{x}=-\dfrac{18}{72}=\dfrac{-1}{4}\\\dfrac{-y}{8}=\dfrac{-18}{72}=\dfrac{-1}{4}\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=20\\y=2\end{matrix}\right.\)
Vậy: (x,y)=(20;2)
\(\dfrac{-5}{x}=\dfrac{-y}{8}=\dfrac{-18}{72}\)
+)\(\dfrac{-5}{x}=\dfrac{-18}{72}\)
\(\Rightarrow x=\dfrac{-5.72}{-18}=20\)
+)\(\dfrac{-y}{8}=\dfrac{-18}{72}\)
\(\Rightarrow-y=\dfrac{-18.8}{72}=-2\)
\(\Rightarrow y=2\)