a)\(\left(3-2x\right)\left(x+1\right)\ge0\)
TH1: \(\hept{\begin{cases}3-2x\ge0\\1+x\ge0\end{cases}\Leftrightarrow\hept{\begin{cases}x\le\frac{3}{2}\\x\ge-1\end{cases}}}\)\(\Leftrightarrow-1\le x\le\frac{3}{2}\)
TH2: \(\hept{\begin{cases}3-2x\le0\\1+x\le0\end{cases}\Leftrightarrow\hept{\begin{cases}x\ge\frac{3}{2}\\x\le-1\end{cases}}}\)( vô lí)
b) \(\left(2x-4\right)\left(x+3\right)\le0\)
\(\Leftrightarrow2\left(x-2\right)\left(x+3\right)\le0\)
TH1:\(\hept{\begin{cases}x-2\le0\\x+3\ge0\end{cases}\Leftrightarrow\hept{\begin{cases}x\le2\\x\ge-3\end{cases}\Leftrightarrow}-3\le x\le2}\)
TH2:\(\hept{\begin{cases}x-2\ge0\\x+3\le0\end{cases}\Leftrightarrow\hept{\begin{cases}x\ge2\\x\le-3\end{cases}}}\)(vô lí)
