∵x-y=6,xy=-1∴(2x+3y-2xy)-(x+4y+xy)-(3yx+2x-2y)=2x+3y-2xy-x-4y-xy-3yx-2x+2y=(2-1-2)x+(3-4+2)y+(-2-1-3)xy=-x+y-6xy=-(x-y)-6xy=-6-6×(-1)=-6+6=0
解:原式=y-x-6xy=0
原式=2x+3y-2xy-x-4y-xy-3xy-2x+2y=-x+y-6xy=6-6*(-1)=12
合并同类项得-x y-6xy=0