\(\Leftrightarrow\left\{{}\begin{matrix}x+my=3m\\m^2x-my=m^3-2m\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}\left(m^2+1\right)x=m\left(m^2+1\right)\\y=mx-m^2+2\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=m\\y=2\end{matrix}\right.\)
\(\left(x-1\right)\left(m-y\right)< 0\)
\(\Leftrightarrow\left(m-1\right)\left(m-2\right)< 0\)
\(\Rightarrow1< m< 2\)