化简求值2x²y-[x²y+2(x²y-xy)]+y,其中x²=2x+1,y=2

化简求值：x-y/x²-2xy+y²-xy+y²/x²-y²,其中(x 化简求值：(x+y)(x-y)+(x-y)²-(6x²y-2xy²)÷2y,其中x=-2, 化简求值3x[xy-2x(y-2x)]+3y(x²-y²),其中x=-1,y=2 化简求值 【2x²-(x+y)(x-y)][(x+y-1)(x-y+1)+1-2y],其中x=-1,y=-2 化简求值3x²y-[2xy-2（xy-3/2x²y)+xy]+3xy²其中x=3、y=-1 (x+y)(x-2y)(x²-4y²) 其中x=8 y=-8 化简求值 化简求值:(x+2y)²-(x+y)(x-y),其中x=-2,y=二分之一 化简求值 分式x²-4/xy-x+2y-2,其中x=-8,y=1/2 化简求值(xy-x²)/xy分之x²-2xy+y²乘x²分之x-y,其中y=二分 化简求值:(-1/3XY)²[xy(2x-y)-2x(xy-y²)],其中X=-3/2,Y=-2 化简求值：(x²-2y²)(x+2y)-2xy(x-y)其中x=-2,y=-½ 化简求值(x+y)(x-y)-(x-y)²-6x²y/2y+(2xy)²/(-4xy)其中