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