Đáp án: $\left( {x;y} \right) = \left\{ {\left( {3;2} \right);\left( {1; - 4} \right);\left( { - 3;0} \right)} \right\}$
Giải thích các bước giải:
$\begin{array}{l}
\left( {x - 2} \right)\left( {xy - 1} \right) = 5 = 1.5 = \left( { - 1} \right).\left( { - 5} \right)\\
\Rightarrow \left[ \begin{array}{l}
\left\{ \begin{array}{l}
x - 2 = 1\\
xy - 1 = 5
\end{array} \right.\\
\left\{ \begin{array}{l}
x - 2 = 5\\
xy - 1 = 1
\end{array} \right.\\
\left\{ \begin{array}{l}
x - 2 = - 1\\
xy - 1 = - 5
\end{array} \right.\\
\left\{ \begin{array}{l}
x - 2 = - 5\\
xy - 1 = - 1
\end{array} \right.
\end{array} \right. \Rightarrow \left[ \begin{array}{l}
\left\{ \begin{array}{l}
x = 3\\
y = 2
\end{array} \right.\\
\left\{ \begin{array}{l}
x = 7\\
y = \frac{2}{7}\left( {ktm} \right)
\end{array} \right.\\
\left\{ \begin{array}{l}
x = 1\\
y = - 4
\end{array} \right.\\
\left\{ \begin{array}{l}
x = - 3\\
y = 0
\end{array} \right.
\end{array} \right.\\
Vậy\,\left( {x;y} \right) = \left\{ {\left( {3;2} \right);\left( {1; - 4} \right);\left( { - 3;0} \right)} \right\}
\end{array}$
