\(\left\{{}\begin{matrix}3x-y=2m-1\\x+2y=3m+2\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}6x-2y=4m-2\\x+2y=3m+2\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}6x-2y+x+2y=4m-2+3m+2\\x+2y=3m+2\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}7x=7m\\2y=3m+2-x\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x=m\\2y=3m+2-m=2m+2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=m\\y=m+1\end{matrix}\right.\)
\(x^2+2y^2=9\)
=>\(m^2+2\left(m+1\right)^2=9\)
=>\(m^2+2m^2+4m+2-9=0\)
=>\(3m^2+4m-7=0\)
=>(3m+7)(m-1)=0
=>\(\left[{}\begin{matrix}3m+7=0\\m-1=0\end{matrix}\right.\)
=>\(\left[{}\begin{matrix}m=-\dfrac{7}{3}\\m=1\end{matrix}\right.\)
mà m nguyên
nên m=1