\(a,\\ 2.\left|3x-1\right|+1=5\\ \Leftrightarrow2.\left|3x-1\right|=5-1=4\\ \Leftrightarrow\left|3x-1\right|=\dfrac{4}{2}=2\\ \Leftrightarrow\left[{}\begin{matrix}3x-1=2\\3x-1=-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}3x=3\\3x=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-\dfrac{1}{3}\end{matrix}\right.\)
\(b,\\ \left|\dfrac{x}{2}-1\right|=3\\ \Leftrightarrow\left[{}\begin{matrix}\dfrac{x}{2}-1=3\\\dfrac{x}{2}-1=-3\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}\dfrac{x}{2}=4\\\dfrac{x}{2}=-2\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=8\\x=-4\end{matrix}\right.\)
