`\text{~~Holi~~}`
`(x^2-5x+6)\sqrt{4-x}<0`
`ĐKXĐ: x\le4`
`->`\(\left[ \begin{array}{l}\begin{cases}x^2-5x+6<0\\\sqrt{4-x}>0\end{cases}\\\begin{cases}x^2-5x+6>0\\\sqrt{4-x}<0\end{cases}\end{array} \right.\)
`->`\(\left[ \begin{array}{l}\begin{cases}x\in(2,3)\\x\in\mathbb{R}\backslash \{4\}\end{cases}\\\begin{cases}x\in(-∞,2)∪(-3,+∞)\\x\in∅\end{cases}\end{array} \right.\)
`->`\(\left[ \begin{array}{l}x\in(2,3)\\x\in∅\end{array} \right.\)
`-> x\in(2,3), x\le4`
`-> x\in(2,3)`
