Vì 2 đt cắt trên trục Ox nên \(y=0\)
\(\Leftrightarrow\left\{{}\begin{matrix}\left(m-3\right)x+m^2+7=0\\x-2=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}2\left(m-3\right)+m^2+7=0\\x=2\end{matrix}\right.\\ \Leftrightarrow2m-6+m^2+7=0\\ \Leftrightarrow\left(m+1\right)^2=0\Leftrightarrow m=-1\)