请说明：若x^2+y^2+z^2=xy-yz-xz,且xyz不等于0,则x=y= -z

请说明:若X^2 + 2Y^2 + Z^2=XY-YZ-XZ,且XYZ不等于0,则X=Y=-Z x/3=y/4=z/5,xyz不等于0,则(xy-2yz+xz)/(2x^-y^+z^)的值为 2^x=5^y=10^z(xyz不等于0）求证xy=yz+xz 1.已知2x-3y+z=0,3x-2y=6z,且xyz不等于0,求xy+yz+xz分之x^2+y^2+z^2的值 设x,y,z∈R+,xy+yz+xz=1,证明不等式:(xy)^2/z+(xz)^2/y+(yz)^2/x+6xyz≥x 设x,y,z≥0,且x+y+z=1,求证：0≤xy+yz+xz-2xyz≤7/27 已知x^3+y^3-z^3=96,xyz=4,x^2+y^2+z^2-xy+xz+yz=12,则x+y-z等于 已知x+y-z=0,2x-y-8z=0,且xyz不等于0,则x2+y2+z2/（xy+yz+zx)等于 已知x、y、z均为正实数,且xy+yz+xz=4xyz,则x/yz+y/xz+z/xy的最小值为多少? 已知：xy/(x+y)=a,xz/(x+z)=b,yz/(y+z)=c,且abc不等于0,求证:x=2abc/(bc+a 已知：xy/(x+y)=a,xz/(x+z)=b,yz/(y+z)=c,且abc不等于0,求证：x=2abc/(bc+a 已知4x-3y-6z=0,x+2y-7z=0,xyz不等于0,求xy+2yz+xz分之2x^2+3y^2+6z^2