(x²+2xy+y²)(x²-xy+y²)²
计算:(xy-x²)×x-y/xy
x²/xy-x/y
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
计算:x²+2xy+y²/xy-y².x²-2xy+y²/xy+y
[-xy/(x-y)²]²×(y²-xy/x)³
x/xy-y²与y/x²-xy 通分
X²+2xy+y²/xy乘x²-2xy+y²/xy+y²=
因式分解xy²-2xy+x+2y-1
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy
先化简,再求值:{xy(x²-3y)+3xy²}(-2xy)+x³y²(2x-y
化简2XY+(X-Y)²