概车纶与款理统外 p4x-r-X80⑨-4 Px=ar-288))8 P4x=1r==6)⑨8 Pw=2r=明=8B8)=8P{X = 0,Y = 2} P{X = 1,Y = 0} P{X = 2,Y = 0} P{X = 1,Y = 1} , 14 3 2 8 0 3 1 2 1 3  =                        = , 28 1 2 8 0 3 2 2 0 3  =                        = , 28 9 2 8 1 3 0 2 1 3  =                        = . 28 3 2 8 0 3 0 2 2 3  =                        =