`**) |x| = |y| <=>` \(\left[ \begin{array}{l}x=y\\x=-y\end{array} \right.\)
Giải:
`|x - 2| - |1 - 2x| = 0`
`=> |x - 2| = |1 - 2x|`
`=>` \(\left[ \begin{array}{l}x-2=1-2x\\x-2=-(1-2x)\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x+2x=1+2\\x-2=-1+2x\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}3x=3\\-2+1=2x-x\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=1\\-1=x\end{array} \right.\)
Vậy `x = +-1`
