(d1) song song với (d2) khi :
\(\left\{{}\begin{matrix}2-m^2=m\\m-5\ne3m-7\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}m^2+m-2=0\\2m\ne2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}\left(m-2\right)\left(m+1\right)=0\\m\ne1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}\left[{}\begin{matrix}m=2\left(TM\right)\\m=-1\left(TM\right)\end{matrix}\right.\\m\ne1\end{matrix}\right.\)