5xy²-{2x²y-[3xy²-(4xy²-2xy²)]}=

-3(xy-2x²)-[y²-(5xy-4x²)+2xy] 已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值 已知x:y=3:2,求(x²+3xy)/(xy+2xy) X²+2xy+y²/xy乘x²-2xy+y²/xy+y²= 3xy²-[xy-2(xy-3/2x²y)+3xy²]+3xy²,其中x=3,y 化简求值 已知：（x+2）2;+|y+1|=0求5xy²-｛2xy²-[3xy²（4xy& 化简求值：【4（xy-1）²-(xy+2)(2-xy)】÷¼xy,其中x=-3,y=1/5 化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1, 3x²y+xy²-[2xy²-4x²y+（x²y-2xy²） (2x²y-3xy²)-3(x²y-2xy²)+2（x²y-4xy&# 计算：(xy-x²)×x-y/xy 合并同类项：(2xy²+3xy²)-(6x²y-3xy²)