\(\left(x-1\right)\left(2x-y\right)=3\)
\(\Leftrightarrow\left(x-1;2x-y\right)\in\left\{\left(-1;-3\right);\left(1;3\right);\left(3;1\right)\right\}\)
\(\Leftrightarrow\left(x;2x-y\right)\in\left\{\left(0;-3\right);\left(2;3\right);\left(4;1\right)\right\}\)
\(\Leftrightarrow\left(x,y\right)\in\left\{\left(0;3\right);\left(2;1\right);\left(4;7\right)\right\}\)