1/2x^2y-1/3xy-0.5x^2y+0.5xy 其中X＝3 y＝-2怎么写啊 请求大仙下凡啊

计算3xy[2xy-x(y-2)+x-1] 1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y) 若1/x-1/y=2,求3x-2xy-3y/x-xy-y的值3x-2xy-3y/x-xy-y 不好意思，是3x-2xy-3y/x-2xy-y .(x+y-2)(x+y-2xy)+(xy-1)^2 因式分解x^2y^2+x^2y+xy^2+3xy+x+y+1 xy(xy+1)+xy+3-2(x+y+1/2)-(x+y-1)^2因式分解 (-1/3xy)^2•[xy(2x-y)-2x(xy-y^2)] (-3分之1xy)的平方×[xy(2x-y)-2x(xy-y的平方)] XY(XY+3)+(XY+4)+4(X+Y+1)-(X+Y+2) 分解因式（x^2+3x+2)(3+8x+4x^2)-90xy(xy+1)+(xy+3)-2(x+y+0.5)-(x+y-1)^2 化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,y=-2 （x+2y-3xy)-(-2x-y+xy),其中x+y=1/2,xy=-1/2 已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y) 已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y= (x+y)(x+y+2xy)+(xy+1)(xy-1)(x+y)(x-y)+4(y-1) 计算：(5-xy/x^3-x^2y)/(1-5/xy)^2*(y-x)^3 计算：1-2x+x^2/x-x^3*xy+x^2y/x-x^2 x²-y²+5x+3y+4（x+y-2xy)(x+y-z)+(xy-1）²