\(\left\{{}\begin{matrix}2x+3y+4=0\\3x+y-1=0\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}x=1\\y=-2\end{matrix}\right.\)
Pt có nghiệm duy nhất khi:
\(\left[{}\begin{matrix}2m.1+5.\left(-2\right)-m=0\\\frac{2m}{2}=\frac{5}{3}=-\frac{m}{4}\\\frac{2m}{3}=\frac{5}{1}=\frac{-m}{-1}\end{matrix}\right.\)
\(\Rightarrow m=10\)