\(\Leftrightarrow m^2x-mx-2x+m-2=0\)
\(\Leftrightarrow m^2x-4x-mx+2x+m-2=0\)
\(\Leftrightarrow x\left(m-2\right)\left(m+2\right)-x\left(m-2\right)+\left(m-2\right)=0\)
\(\Leftrightarrow\left(mx+2x-x+1\right)\left(m-2\right)=0\)
\(\Leftrightarrow\left(\left(m+1\right)x+1\right)\left(m-2\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=-\frac{1}{m+1}\\m=2\end{matrix}\right.\) m=2 thì TM mọi x thuôộc R