3x+5y=k+2 (1)2x+3y=k (2)将(2)代入(1)得:3x+5y=2x+3y+2(3)x+2y=2x+y+y=2y=2将y=2代入(3)得3x+10=2x+6+2x=-2将x=-2 y=2代入(1)得-6+10=k+2k=-2