a/ \(1-4x\ge0\Rightarrow x\le\frac{1}{4}\)
b/\(3-4x\ne0\Rightarrow x\ne\frac{3}{4}\)
c/ \(2x-2< 0\Rightarrow x< 1\)
d/ \(\left\{{}\begin{matrix}4x+2\ne0\\1+3x\ge0\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}x\ne-\frac{1}{2}\\x\ge-\frac{1}{3}\end{matrix}\right.\) \(\Rightarrow x\ge-\frac{1}{3}\)