`| x - 1| - 2 - x = 0`
`=> | x - 1| = 0 + 2 + x = 2 + x`
`=>`\(\left[ \begin{array}{l}x - 1 = 2 + x\\x - 1 = -2 - x\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}x - x = 2 + 1\\x + x = -2 + 1\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}0=3 ( vô lí)\\2x=-1\end{array} \right.\)
`=> x = -1/2`