ĐKXĐ:
a/ \(3x+1\ge0\Leftrightarrow x\ge-\frac{1}{3}\)
b/ \(\left\{{}\begin{matrix}x\ge0\\1-\sqrt{x}\ne0\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}x\ge0\\x\ne1\end{matrix}\right.\)
c/ \(25-x^2\ge0\Rightarrow-5\le x\le5\)
d/ \(4x^2-4x+1>0\Leftrightarrow\left(2x-1\right)^2>0\Leftrightarrow x\ne\frac{1}{2}\)