快,3分钟,已知x+y=2,xy=2/3求x^2y+xy^2(x-y)^2

快,3分钟,已知x+y=2,xy=2/3求x^2y+xy^2(x-y)^2 已知x(x-1)-(x^2-y)=-3求（二分之y-x+2xy)-xy 快, 已知xy=-2,x-y=3,求整式（-3xy-7y）+[4x-3(xy+y-2x)]的值快 急需 已知(y+2x)/xy=3/2,求(4x+3xy+2y)/(-4x+8xy-2y)快.主要是过程. 已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方在线等,快,好了加分!为什么（x*+y*)/(xy) =(x/y+y/x) 啊 ？不懂，还没学。懂了！！！！！thanks 已知x-y=-1,xy=3.求x^3y-2x^2y^2+xy^3的值快 已知x分之1+y分之1=5,则分式x+2xy+y分之2x-3xy+2y的值为快 由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少? 已知xy^2=-2,求-xy（x^2y^5-xy^3-y)的值. 已知xy^2=-2 求-xy(x^2y^5-xy^3-y) 已知xy^2=-2xy(x^2y^5-xy^3-y) 已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理.已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理. 已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2 已知x+xy+y=3,则(3x+2xy+3y)/(2x+xy+2y)= 已知x-y=3xy,则2x+3xy-2y除以x-2xy-y=? 已知x-y=3xy,则2x+3xy-2y/x-2xy-y= 已知x+y分之xy=2,那么3x-5xy+3y分之3xy-x-y= 已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y=