x²-2xy-2x+y²+2y+1
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
【(1)/(x-y)+(1)/(x-y)】÷(2x)/(x²-2xy+y²)
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
计算:x²+2xy+y²/xy-y².x²-2xy+y²/xy+y
因式分解xy²-2xy+x+2y-1
多项式因式分解 1,(x-y)³-(x-y)²(x+y) 2,x(x²-xy)-(4x
(x+y-2xy)(x+y-2)+(1-xy)²
(-x-2y)(x²-2xy+4y²)
x²-xy-2y²-x-y 因式分解
x³y-2x²y²+xy³
化简:[(x+y)²-(x-y)²]÷2xy
若x=1/2,y=1 求x(x²+xy+y²)-y(x²+xy+y²)+3xy(