(2x+1)(xy-2)=2xy X-2y=4 求x,y速度呀

3xy(x^2-xy^2+xy)-xy^2(2x^2-xy+2x) 化简:xy分之3x^2+2xy-xy分之2x^2-xy= 已知x+y=1,xy=-2,则x²y+xy²-2xy 1-2/x+y=xy,4y+6x=xy.求xy的解? 已知（x+1）*（x+1）=-Iy-1I,求2（xy-（5xy）*（5xy））-3（（xy）*（xy）-xy） ( )-(x^2+3xy)=-xy-1/3y^2 因式分解2x^-xy .(x+y-2)(x+y-2xy)+(xy-1)^2 因式分解x^3+2xy-x-xy^2= 计算3xy[2xy-x(y-2)+x-1] 1-(3xy-x)+【-2(2x+3xy)】 （-3x^y+2xy)-( )=4x^+xy x³+2xy-x-xy²=（因式分解) (XY-X^2)除以X-Y/XY=? 已知1/x-1/y=2,求3x+7xy-3y/2x-3xy-2y答案是1/x-1/y=2(y-x)/xy=2 得：x-y=-2xy(3x+7xy-3y)/(2x-3xy-2y)=[3(x-y)+7xy]/[2(x-y)-3xy]=(-6xy+7xy)/(-4xy-3xy)=xy/(-7xy)=-1/7 谁能帮我解释一下=[3(x-y)+7xy]/[2(x-y)-3xy]=(-6xy+7xy)/(-4xy-3xy) 是怎 因式分解X^3-2xy+xy^2 x^2-xy/xy-y^2约分 因式分解:-xy^2+2xy-x