1, \(ĐK:x-1\ne0\Rightarrow x\ne1\)
\(\Rightarrow\) D = (\(-\infty\);1) \(\cup\)(1;\(+\infty\))
2,ĐK: \(\left\{{}\begin{matrix}4x-2\ge0\\4-x\ge0\end{matrix}\right.\Rightarrow\)\(\left\{{}\begin{matrix}x\ge\frac{1}{2}\\x\le4\end{matrix}\right.\) \(\Rightarrow\frac{1}{2}\le x\le4\)
D = [\(\frac{1}{2};4\)]