$(x+1).(xy-2)=11$
\(\left[ \begin{array}{l}x+1=11\\xy-2=1\end{array} \right.\) ⇒ \(\left[ \begin{array}{l}x=10\\xy=3⇒x=±1; ±3, y=±3; ±1\end{array} \right.\)
\(\left[ \begin{array}{l}x+1=1\\xy-2=11\end{array} \right.\) ⇒ \(\left[ \begin{array}{l}x=2\\xy=14 ⇒ x= ±1; ±2; ±7; ±14, y=±14; ±7; ±2; ±1\end{array} \right.\)
\(\left[ \begin{array}{l}x+1=-1\\xy-2=-11\end{array} \right.\) ⇒ \(\left[ \begin{array}{l}x=0\\x=-13 ⇒ x=±1; ±13, y=±13; ±1\end{array} \right.\)
\(\left[ \begin{array}{l}x+1=-11\\xy-2=-1\end{array} \right.\) ⇒ \(\left[ \begin{array}{l}x=-10\\x=-3 ⇒ x=±1; ±3, y=±3; ±1\end{array} \right.\)