\(\Leftrightarrow\left\{{}\begin{matrix}x>=\dfrac{1}{2}\\\left(2x-1-x+1\right)\left(2x-1+x-1\right)=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x>=\dfrac{1}{2}\\x\cdot\left(3x-2\right)=0\end{matrix}\right.\Leftrightarrow x=\dfrac{2}{3}\)
`@ x >= 1 -> x - 1 = 2x - 1`
`<=> 0 = x`
`-> x = 0 (ktm)`
`@ x < 1 -> 1 - x = 2x - 1`
`<=> 3x = 2`
`<=> x = 2/3 ( tm)`