a) \(x\left(x-1\right)+2x-2=0\)
\(\Leftrightarrow x\left(x-2\right)+2\left(x-1\right)=0\)
\(\Leftrightarrow\left(x+2\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=1\end{matrix}\right.\)
b) \(\left(3x-1\right)^2-\left(x+5\right)^2=0\)
\(\Leftrightarrow\left(3x-1-x-5\right)\left(3x-1+x+5\right)=0\)
\(\Leftrightarrow\left(2x-6\right)\left(4x+4\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}2x=6\\4x=-4\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-1\end{matrix}\right.\)