Tìm x, y biết: (x - 1) . (xy - 3) = 3; (x - 3) . (2y + 1) = 7; (2x + 1) . (3y - 2) = -55

(x-1). ( xy-3)=3
(x-3).(2y+1)=7
(2x+1).(3y-2)=-55
(2x+1).(3y-2)=-35
(2x+1).(y-3)=10
(3x-2).(2y-3)=1
(x-7).(xy=1)=9