2x²y＋｛2xy-[x²y-2(﹣3x²y+xy)]﹣4xy²｝ 计算

2x²y＋｛2xy-[x²y-2(﹣3x²y+xy)]﹣4xy²｝ 计算 计算：x²+2xy+y²/xy-y².x²-2xy+y²/xy+y&# 计算 2xy[4x²y²-3y（xy+x²y）-xy²] 计算：(xy-x²)×x-y/xy 3x²y+xy²-[2xy²-4x²y+（x²y-2xy²） (2x²y-3xy²)-3(x²y-2xy²)+2（x²y-4xy&# 计算：（-7x²y）（2x²y-3xy³+xy） 计算：2x+2y分之3y + x²+xy分之2xy x-y/x²÷x²-2xy+y²/xy*（xy-x²） 计算；（xy-x²）÷x²-2xy+y²/xy · x-y/x² 计算3x[xy-2x(1/y-x/3]+3y(x²-y²) -3(xy-2x²)-[y²-(5xy-4x²)+2xy]