已知三个数xyz满足x加y分之xy
来源:学生作业帮助网 编辑:作业帮 时间:2024/04/27 23:35:14
x=1,y=2,z=310,11,12,13,21,31Aborrow从..借,他应该是向妈妈借钱lent借给有yesterday用过去式还有mothe是mother吧?
若x+y=x-y则y=0,不可能则xy=x/yy=1或y=-1y=1,x+y≠xy,x-y≠xy,不符合条件所以y=-1若x+y=xy即x-1=-x,则x=1/2若x-y=xy则x+1=-xx==-1
XY/X+Y=-2,-->(x+y)/(xy)=-1/2,-->1/x+1/y=-1/2YZ/Y+Z=4/3,-->(y+z)/(yz)=3/4,-->1/y+1/z=3/4&
倒数解方程组..(x+y)/xy=1/x+1/y=-1/2类推~~~
x/2=y/3=z/4=tx=2ty=3tz=4tx+y-z=1/122t+3t-4t=t=1/12x=1/6y=1/4z=1/3xyz=1/6*1/4/*1/3=1/72
XYZ>0,则X.Y.Z中全正上式为3X.Y.Z中一正两负为-1
xy/(x+y)=-2(x+y)/(xy)=-1/2,1/x+1/y=-1/2yz/(y+z)=4/3,(y+z)/(yz)=3/4,1/y+1/z=3/4zx/(z+x)=-4/3,(z+x)/(z
xyz=x+y+z<3z∴xy<3由于x<y,故xy=2,x=1,y=2∴z=3
∵xyx+y=-2,yzy+z=43,zxz+x=-43,∴1x+1y=-12,1y+1z=34,1z+1x=-34,∴2(1x+1y+1z)=-12,即1x+1y+1z=-14,则xyzxy+yz+
题目有问题,yx/(y+x)=4/3应该是yz/(y+z)=4/3xy/(x+y)=-2(x+y)/(xy)=-1/21/x+1/y=-1/2(1)yz/(y+z)=4/3(y+z)/(yz)=3/4
x分之负x+y分之负y+z分之负z的值为-3
∵x加(y分之1)等于1∴xy+1=y∴xyz=yz-z∵y加(z分之1)等于1∴yz+1=z即yz-z=-1∴xyz=-1
-4再问:请问第三步是怎么算出-1/4的可以写一下过程么再答:1/x+1/y+1/y+1/z+1/z+1/x=2(1/x+1/y+1/z)=-1/2∴1/x+1/y+1/z=-1/2/2=-1/4
可知:1/x+1/y=-2……①1/y+1/z=4/3……②1/z+1/x=-4/3……③①+②+③得:1/x+1/y+1/z=-1……④④-①得:1/z=1④-②得:1/x=-7/3④-③得:1/y
条件应该是xyz=8吧,假设是,如下:1/x+1/y+1/z=(yz+xz+xy)/xyz=(yz+xz+xy)/8将z=-x-y代入上式,也可代入x=-z-y或y=-z-x得分子:y(-x-y)+x
xy/(x+y)=-2(x+y)/xy=-1/21/y+1/x=-1/2yz/(y+z)=4/3(y+z)/yz=3/41/z+1/y=3/4zx/(z+x)=-4/3(z+x)/zx=-3/41/x
xy/x+y=-2,取倒数就得1/x+1/y=-1/2①yz/y+z=3/4取倒数就得1/y+1/z=4/3②zx/z+x=-3/4取倒数就得1/x+1/z=-4/3③①+②+③就得2(1/x+1/y
解题思路:本题的关键是将三个方程两边取倒数,化简后分别将方程等号左边和右边相加,得到1/x+1/y+1/z的值,最后将要求的分式化简,把1/x+1/y+1/z的值带入即可。解题过程: