xy+x+y+1=12
(x+1)(y+1)=12
所以x+1=1,y+1=12或x+1=2,y+1=6或x+1=3,y+1=4或x+1=4,y+1=3或x+1=6,y+1=2或x+1=12,y+1=1
所以x=0,y=11或x=1,y=5或x=2,y=3或x=3,y=2或x=5,y=1或x=11,y=0