化简x²+xy/x²-xy÷(x+y)÷-x/y²-xy
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
计算:(xy-x²)×x-y/xy
x²/xy-x/y
化简:[(x+y)²-(x-y)²]÷2xy
(xy-x²)²÷(x-y)²/xy·x-y/x² 计算
1.化简:x²-4y²/x²+y²+2xy÷2y+x/x²+xy.
2x(x²y-xy²)+xy(xy-x²)]÷x²y等于多少
计算;(xy-x²)÷x²-2xy+y²/xy · x-y/x²
[-xy/(x-y)²]²×(y²-xy/x)³
x/xy-y²与y/x²-xy 通分
化简{-xy/(x-y)²}四次方×(y²-xy/x)³×x四次方/y十次方÷(x/xy-
计算:(xy-x²)乘 x-y分之xy