在算式1/18+1/x+1/y+1/z=1中,xyz分别代表三个不同的自然数接题：则这三个数的和是多少?

已知 x/(y+z)+y/(z+x)+z/(x+y)=1求 (x*x)/(y+z)+(y*y)/(x+z)+(z*z)/(x+y)=? 1.已知X:Y:Z=1:2:3,且3X-4Y+5Z=12,求解算式3X-5Y+Z的值. 若实数XYZ满足2|x-y|+√2y+z+z方-z+1//4=0 求X+Y+Z 2y+z在根号里 解方程 x-2y+z/9=2x+y+3x/10=3x+2y-z/3=1 要算式和答案 X+y+z=26,x-y=1,2x-y+z=18 {x+y-z=11 y+z-x=5 z+x-y=1 {x+y-z=11,x-y-z=-5,x-y+z=1 方程组 (1) x+2y-3z=12 x-3y+2z= - 13 x-y-z=0 (2) x+ y=z 5x-y+z=18 2x+5y+3z= -1 在算式1/18+1/x+1/y+1/z=1中,xyz分别代表三个不同的自然数接题：则这三个数的和是多少? x:y:z=2:1:5,2x+3y-z=18,求x,y,z,值 x+y+z=18,x.y是z的1/3,求x,y,z的值 解三元一次方程组 ①2x-y+z=1 3x+y -2z=2 X+2y-z=3 ②x-4y+z=-3 2x+Y-Z=18 X-Y-Z=7 ③4x+4y+2z=7 6X-4y-z=6 2x-y+z=1 x/(y+z)=y/(x+z)=z/(x+y)x/(y+z)=y/(x+z)=z/(x+y)=(x+y+z)/[(x+z)+(x+y)+(y+z)]=1/2y/(x+z)=z/(x+y)=（y-z）/【（x+z）-（x+y）】=-1我知道这是两种情况做法一是x+y+z≠0做法二是x+y+z=0我的疑问是做法二在证明中那里用到了 1、y-x/x²-y²2、(x-y)(y-z)(z-x)/(z-y)(y-x)(x-z) X/Y+Z=Y/X+Z+1=Z/X+Y-1=X+Y+Z,求x+y+z等于多少 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 x+y+z=6 x+2y+3z=14 y+1=z