x y分之x y分之2y-搜答案-搜搜考试网

2/xy=2(y-x)/xy(y-x)3y/(xy-x^2)=3y^2/xy(y-x)如果不懂,请追问,祝学习愉快!

2x+2y分之3y+x²+xy分之2xy=3y/2(x+y)+2xy/x(x+y)=3y/2(x+y)+2y/(x+y)=7y/2(x+y)如追加其它问题,再问：这道题要通分，能不能化成同分

绝对算不出来再答：如果是一道题发图咯再问：x平方减xy加y平方分之x平方加2xy加y平方他给你条件是y分之x等于2分之1xy再问：吧xy无视掉再答：马上再答：化成Y等于2X在带入再问：然后怎么样再答：

3xy-[2xy-2(xy-2分之3xy)+xy]+3xy=6xy-[2xy-2xy+3xy+xy)=6xy-4xy=2xy=2×3×3分之1=2

1/x+1/y=-2则(x-xy+y)/(x+xy+y)分子分母同除以xy=(1/x+1/y-1)/(1/x+1/y+1)=(-2-1)/(-2+1)=3

xy/(x+y)=2∴xy=2(x+y)(3xy-x-y)/(3x-5xy+3y)=[6(x+y)-x-y]/[3x+3y-10(x+y)]=5(x+y)/[-7(x+y)]=-5/7

因为X+Y分之XY=2,所以XY=2(X+Y)代入后面的分子式得：13（X+Y)/5(X+Y)=13/5

原式=3y/2(x+y)+2xy/x(x+y)=(3xy+4xy)/2x(x+y)=7xy/2x(x+y)=7y/(2x+2y)再问：不对再答：哦，不信就算了

（x+2y-3xy)-(-2x-y+xy)=x+2y-3xy+2x+y-xy=(1+2)x+(2+1)y-(3+1)xy=3x+3y-4xy=3(x+y)-4xy=3*1/2-4*(-1/2)=3/2

原式(-xy/3)²*[xy(2x-y)-2x(xy-y²)]=(x²y²/9)(2x²y-xy²-2x²y+2xy²)

3y/(2x+2y)+2xy/(x²+xy)=3y/(2x+2y)+2y/(x+y)=3y/(2x+2y)+4xy/(2x+2y)=7y/(2x+2y)

由已知条件可得：x-y=-4xy,（也就是在等式两边乘xy后整理,即可）,代入所求的式子里分母为-4xy+7xy,即3xy；分子为-4xy-2xy,即-6xy,化简得-2

原式=(x+y)²/y(x-y)*(x-y)²/y(x+y)=(x+y)(x-y)/y²=(x²-y²)/y²

xy/(x+y)=2(x+y)/xy=1/21/x+1/y=1/2(3x-xy+3y)/(-x+3xy-y)=(3/y-1+3/x)/(-1/y+3-1/x)=[3(1/x+1/y)-1]/[(3-(

设x+y=axy=b,则b/a=3b=3a所以-X+3XY-Y分之2X-3XY+2Y可以写成(2a-3b)/(3b-a)=-7/8

xy分之【x加y】等于2分之一xy=2(x+y)【xy加x加y】分之xy=2(x+y)/[2(x+y)+x+y]=2(x+y)/[3(x+y)]=2/3

（xy-x²）÷xy分之x²-2xy+y²乘x²分之x-y=-x(x-y)×xy/(x-y)²×(x-y)/x²=-y∴结果与x的值没有关系

干什么?计算吗?原式=x/y(x²-y²)/(xy)-(xy-y²)/(xy-x²)=(x²-y²)/(xy)-y(x-y)/[x(y-x)

[(xy-2)(-xy-2)-4(xy-1)^2]除以(-xy)=[-x²y²+4-4(x²y²-2xy+1)]÷(-xy)=(-x²y²+