Ta có : \(\dfrac{x}{y}+\dfrac{y}{z}+\dfrac{z}{x}=\dfrac{y}{x}+\dfrac{z}{y}+\dfrac{x}{z}\)
=> \(\dfrac{x}{y}+\dfrac{y}{z}+\dfrac{z}{x}=\dfrac{y}{x}+\dfrac{z}{y}+\dfrac{x}{z}\)=\(\dfrac{x+y+z}{x+y+z}=1\)
=> x=y=z
TH1: x=y=z=1=>x+y+z=3( thỏa )
TH2: x,y,z >1=>x+y+z>3 ( vô lý)
Vậy x=y=z=1