化简： 4xy²-3x²y-｛3x²y+xy²-[2xy²-（4x&#

化简4xy-3y²-3x²+xy-3xy-2x²+x²-2y² -3(xy-2x²)-[y²-(5xy-4x²)+2xy] 3x²y+xy²-[2xy²-4x²y+（x²y-2xy²） (2x²y-3xy²)-3(x²y-2xy²)+2（x²y-4xy&# 计算 2xy[4x²y²-3y（xy+x²y）-xy²] 计算：(xy-x²)×x-y/xy -4x²y-8xy²+2x²y-3xy² 化简3/（x²+2xy+y²）-4/（x²-2xy+y²）+5/（x² 化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1, x²/xy-x/y 化简(x²y-4y²)/(x²+4xy+4y²)*[(4xy)/(x-2y)+x 已知x:y=3:2,求(x²+3xy)/(xy+2xy)