(-2x-8).(3y+9)=0
\(\left[ \begin{array}{l}-2x-8=0\\3y+9=0\end{array} \right.\)
\(\left[ \begin{array}{l}-2x=0+8\\3y=0-9\end{array} \right.\)
\(\left[ \begin{array}{l}-2x=8\\3y=-9\end{array} \right.\)
\(\left[ \begin{array}{l}x=8:(-2)\\x=-9:3\end{array} \right.\)
\(\left[ \begin{array}{l}x=-4\\x=-3\end{array} \right.\)
Vậy (x,y)=(-4,-3)