(3x²y-xy²+1/2xy)÷(-1/2xy)
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
下列多项式:(1)x²+xy-y²;(2)-x²+2xy-y²;(3)xy+x&
化简求值3x²y-[2xy-2(xy-3/2x²y)+xy]+3xy²其中x=3、y=-1
化简求值:【4(xy-1)²-(xy+2)(2-xy)】÷¼xy,其中x=-3,y=1/5
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
先化简,再求值 ⒈2(Xy+Xy)-3(Xy-xy)-4Xy,其中X=1,y=-1
化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,
计算3xy[2xy-x(y-2)+x-1]
xy(xy+1)+(xy+3)-2(x+y+2分之一)-(x+y-1)的平方
(-3分之1xy)的平方×[xy(2x-y)-2x(xy-y的平方)]
(1)-2分之1xy(3y²-2xy+3x²y)