ĐKXĐ: x$\neq$ 1
`{2x-4}/{-x+1}`≤0
⇔ \(\left[ \begin{array}{l}2x-4≤0\\-x+1>0\end{array} \right.\) hoặc \(\left[ \begin{array}{l}2x-4≥0\\-x+1<0\end{array} \right.\)
⇔ \(\left[ \begin{array}{l}x≤2\\x<1\end{array} \right.\) hoặc \(\left[ \begin{array}{l}x≥2\\x>1\end{array} \right.\)
