计算：1.{2x(x²y+xy²)-4xy(xy-x²)}÷(-2x²y)

计算：(xy-x²)×x-y/xy x-y/x²÷x²-2xy+y²/xy*（xy-x²） 计算；（xy-x²）÷x²-2xy+y²/xy · x-y/x² 计算：x²+2xy+y²/xy-y².x²-2xy+y²/xy+y&# 计算 2xy[4x²y²-3y（xy+x²y）-xy²] 计算x²y³-2x(4xy³) 1.化简：x²-4y²/x²+y²+2xy÷2y+x/x²+xy. 计算：（xy-x²）乘 x-y分之xy x²/xy-x/y (xy-x²）²÷（x-y)²/xy·x-y/x² 计算 计算xy-y²分之x²+2xy+y²÷x²-2xy+y²分之xy+y& .先化简,后计算.[2x(x²y-xy²)+xy(xy-x²)]/x²yx=20