先化简,再求值3x²y-[2xy-2(xy-2/3x²y)+xy]=3x²y-2xy+2(xy-2/3x²y)-xy=3x²y-2xy+2xy-4/3x²y-xy=5/3x²y-xy=xy(5/3x-1)将x=3,y=-1/3 代入原式=xy(5/3x-1)=3×(-1/3)(5/3×3-1)=-1×...