2xy - 2x + 3y = 24 , x,y € Z*
2xy-2x+3y-3=24-3
2x(y-1)+3(y-1)=21
(2x+3)(y-1)=21
21= -21•(-1)=-7• (-3)=-3•(-7)=-1•(-21)=1•21=3•7=7•3=21•1
2x+3=-21 si y-1=-1 => x= -12 si y=0
2x+3=-7 si y-1=-3 => x= -5 si y= -2
2x+3=-3 si y-1=-7 => x= -3 si y= -6
2x+3=-1 si y-1=-21 => x=-2 si y=-20
2x+3=1 si y-1=21 => x=-1 si y=22
2x+3=3 si y-1=7 => x=0 si y=8
2x+3=7 si y-1=3 => x=2 si y=4
2x+3=21 si y-1=1 => x=9 si y=2
