x²+y²+z²-xy-xz-yz=0
2x²+2y²+2z²-2xy-2xz-2yz=0
(x²-2xy+y²)+(y²-2yz+z²)+(z²-2zx+x²)=0
(x-y)²+(y-z)²+(z-x)²=0
所以x=y=z
此题如仍有疑问,欢迎追问!
x²+y²+z²-xy-xz-yz=0
2x²+2y²+2z²-2xy-2xz-2yz=0
(x²-2xy+y²)+(y²-2yz+z²)+(z²-2zx+x²)=0
(x-y)²+(y-z)²+(z-x)²=0
所以x=y=z
此题如仍有疑问,欢迎追问!