a, 3x ( y+1) + nó + 1 = 7(y+1)(3x +1) =7th1 : \(\left\{{}\begin{matrix}y+1=1\\3x+1=7\end{matrix}\right. \) => \(\left\{{}\begin{matrix}y=0\\x=2\end{matrix}\right. \)th2: \(\left\{{}\begin{matrix}y+1=-1\\3x+1=-7\end{matrix}\right...