要使x-y分之x y无意义-搜答案-搜搜做题作业网

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

答案是零,左边约分剩下x/y

1）若x,y同为正数,则x分之|x|+y分之|y|+xy分之|xy|=1+1+1=32）若x,y同为负数,则x分之|x|+y分之|y|+xy分之|xy|=-1-1+1=-13）若x,y异号,比如x为正

=(xy-x的平方）除以(x的平方-2xy+y的平方\xy)乘以(x-y\x的平方)=-x（x-y）×xy/（x-y）2×（x-y）/x2=-y再问：嗯

当x＝（　y）时,分式x＾2－y＾2分之5无意义

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

当x,y满足关系x=y时,分式x-y分之x+y无意义

1除以（1-根号下xy)

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

∵(2x-y)分之2x无意义∴2x-y=0∴y=2x∴(4x-3y)分之x=(4x-6x)分之x=(-2x)分之x=-2分之1很高兴为您解答,【学习宝典】团队为您答题.请点击下面的【选为满意回答】按钮

1、(xy分之x²-y²)×(x-y分之x)-(y分之x)；=(x+y)(x-y)/xy×x/(x-y)-x/y=(x+y)/y-x/y=(x+y-x)/y=12、6xy²

（xy-x²）乘（x-y）分之xy=-x(x-y)乘[(x-y)分之xy]=-x²y

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-(

2/3

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-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)

x-1分之y= 分之xy-y

分子上应写：（x-1）²或者x²-2x+1再问：怎么书面表达呢？能否详细一些，谢谢再答：希望你及时采纳！！！！！