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RMO 2017 P6

Source: RMO 2017 P6

October 8, 2017
inequalities

Problem Statement

Let x,y,zx,y,z be real numbers, each greater than 11. Prove that x+1y+1+y+1z+1+z+1x+1x1y1+y1z1+z1x1\dfrac{x+1}{y+1}+\dfrac{y+1}{z+1}+\dfrac{z+1}{x+1} \leq \dfrac{x-1}{y-1}+\dfrac{y-1}{z-1}+\dfrac{z-1}{x-1}.