（2xy+1/5x）^2(-2y+1/2x)^2(-3a-2b)^2(a-b)^2这四道题是完全平方差2步出来就行

5xy^2-{2x^y-[3xy^2-（xy^2-2x^2y）]/（-1/2xy）} x²-y²+5x+3y+4（x+y-2xy)(x+y-z)+(xy-1）² 1.（xy-1）^2-(x+y-2xy)(2-x-y)2.(x+y)(x+y+2xy)+(xy-1)(xy+1) .(x+y-2)(x+y-2xy)+(xy-1)^2 分解因式：(X+Y）*（X+Y+2XY）+（XY+1）*（XY-1） 5x^2y/-1/2xy*3xy^2 化简!1、（x^2-xy）+xy+y^2 2、3（x^2-xy）-xy+y^2 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) 1/x-1/y=5求（-x+xy+y）/(2x+7xy-2y） (-2xy+2x+5y)-(3xy+2y-2x)-(x+4y+xy)其中x-y=4xy=-1 若x-y=4,xy=1,则(2x+y-2xy)-(3x+2y+xy)-(4xy+3y-5x)= 计算：（1）8x^2y^2*(-3x/4y^5) (2)(x+y)^2/xy-y^2*(y-x)^2/xy+y^2 （-1/2xy）（2/3x^2y-3/2xy^2+6/5y) （x+y）(x-1)-xy-y^2 怎么因式分解? 计算：(5-xy/x^3-x^2y)/(1-5/xy)^2*(y-x)^3 计算3xy[2xy-x(y-2)+x-1] {(x-y/x^2-2xy+y^2)-(xy+y^2/x^2-y^2)}*(xy/y-1)