Ta có:\(x.5=y.3=\dfrac{x}{3}=\dfrac{y}{5}=\dfrac{x}{3}=\dfrac{2y}{2.5}\) Áp dụng tcdtsbn , ta có:\(\dfrac{x}{3}=\dfrac{2y}{2.5}=\dfrac{x}{3}=\dfrac{2y}{10}=\dfrac{-28}{-7}=4\)\(\Rightarrow\left\{{}\begin{matrix}x=12\\y=20\end{matrix}\right.\)Câu trả lời: Ta có:\(x.5=y.3=\dfrac{x}{3}=\dfrac{y}{5}=\dfrac{x}{3}=\dfrac{2y}{2.5}\) Áp dụng tcdtsbn , ta có:\(\dfrac{x}{3}=\dfrac{2y}{2.5}=\dfrac{x}{3}=\dfrac{2y}{10}=\dfrac{-28}{-7}=4\)\(\Rightarrow\left\{{}\begin{matrix}x=12\\y=20\end{matrix}\right.\)