xy-x-y+1/y²-2y+1将其化简?

化简求值3x²y-[2xy-2（xy-3/2x²y)+xy]+3xy²其中x=3、y=-1 化简求值:(-1/3XY)²[xy(2x-y)-2x(xy-y²)],其中X=-3/2,Y=-2 化简求值1.x^2+2xy+y^2/x^2-y^2除以x^2+xy/xy-y^2X=1Y=-2011 化简求值[1-(2x/x+y）]÷ （x²-2xy+y²/3x+3y）+（x²+xy/x& 化简求值：x-y/x²-2xy+y²-xy+y²/x²-y²,其中(x (x+y-2xy)(x+y-2)+(1-xy)² xy-1+x-y 化简求值3x[xy-2x(y-2x)]+3y(x²-y²),其中x=-1,y=2 化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1, 请你先化简分式x²-2xy+y²/x²-xy÷(xy的-1次方-x的-1次方y),再将x= 【(1)/(x-y)+(1)/(x-y)】÷(2x)/(x²-2xy+y²) 1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)