Giúp mình đi huhushsu

Đáp án:

$\begin{array}{l}
\left| {mx - x + 1} \right| = \left| {x + 2} \right|\\
 \Leftrightarrow \left[ \begin{array}{l}
mx - x + 1 = x + 2\\
mx - x + 1 =  - x - 2
\end{array} \right.\\
 \Leftrightarrow \left[ \begin{array}{l}
\left( {m - 2} \right).x = 1\\
mx =  - 3
\end{array} \right.\\
 \Leftrightarrow \left\{ \begin{array}{l}
x = \dfrac{1}{{m - 2}}\left( {m \ne 2} \right)\\
x = \dfrac{{ - 3}}{m}\left( {m \ne 0} \right)
\end{array} \right.\\
Vậy\,x = \dfrac{1}{{m - 2}};x = \dfrac{{ - 3}}{m}\left( {m \ne 2;m \ne 0} \right)
\end{array}$