1)
\(\left|2x-3\right|=2x-3\)
\(\Leftrightarrow\) \(2x-3\ge0\)
\(\Leftrightarrow\) \(2x\ge3\)
\(\Leftrightarrow\) \(x\ge\dfrac{3}{2}\)
2)
\(\left|5x-\dfrac{2}{3}\right|=\dfrac{2}{3}-5x\)
\(\Leftrightarrow\) \(5x-\dfrac{2}{3}\le0\)
\(\Leftrightarrow\) \(5x\le\dfrac{2}{3}\)
\(\Leftrightarrow\) \(x\le\dfrac{2}{15}\)
3)
\(\left|3-x\right|+\left|2y-5\right|\le0\) mà \(\left\{{}\begin{matrix}\left|3-x\right|\ge0\\\left|2y-5\right|\ge0\end{matrix}\right.\)
nên \(\left|3-x\right|+\left|2y-5\right|=0\)
\(\Leftrightarrow\) \(\left\{{}\begin{matrix}\left|3-x\right|=0\\\left|2y-5\right|=0\end{matrix}\right.\) \(\Leftrightarrow\) \(\left\{{}\begin{matrix}3-x=0\\2y-5=0\end{matrix}\right.\) \(\Leftrightarrow\) \(\left\{{}\begin{matrix}x=3\\2y=5\end{matrix}\right.\)
\(\Leftrightarrow\) \(\left\{{}\begin{matrix}x=3\\y=\dfrac{5}{2}\end{matrix}\right.\)