((xy+2)(xy-2)-2x²y²+5(xy-y)²)÷(2xy)
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
计算:x²+2xy+y²/xy-y².x²-2xy+y²/xy+y
-3(xy-2x²)-[y²-(5xy-4x²)+2xy]
X²+2xy+y²/xy乘x²-2xy+y²/xy+y²=
已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值
因式分解xy²-2xy+x+2y-1
2x(x²y-xy²)+xy(xy-x²)]÷x²y等于多少
计算;(xy-x²)÷x²-2xy+y²/xy · x-y/x²
计算xy-y²分之x²+2xy+y²÷x²-2xy+y²分之xy+y&
已知x:y=3:2,求(x²+3xy)/(xy+2xy)
(xy-x^2)乘以(xy)/(x-y)
计算:-2x²y(-2xy²)²+(2xy)³·(xy²)