\(\left\{{}\begin{matrix}2x+3y=m\\25x-3y=3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}2x-m=3y\\25x-3y=3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=\frac{m-2x}{3}\\25x+3x-m=3\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}y=\frac{3-2x}{3}\\27x=3+m\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\frac{3+m}{27}\\y=\frac{m-\frac{6+2m}{27}}{3}=\frac{27m-6-2m}{81}\end{matrix}\right.\)
Mà: \(x>0;y< 0\Rightarrow\left\{{}\begin{matrix}\frac{3+m}{27}>0\\\frac{25m-6}{81}< 0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}m>-3\\m< \frac{6}{25}\end{matrix}\right.\)
\(\Rightarrow m\in\left\{-3;\frac{6}{25}\right\}\)
