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Inequality where a^x=bc,b^y=ca, c^z=ab

Source: 2017 Azerbaijan Senior National Olympiad

April 29, 2022
Inequalityalgebrainequalities

Problem Statement

a,b,c(0,1)a,b,c \in (0,1) and x,y,z(0,)x,y,z \in ( 0, \infty) reals satisfies the condition ax=bc,by=ca,cz=aba^x=bc,b^y=ca,c^z=ab. Prove that 12+x+12+y+12+z34 \dfrac{1}{2+x}+\dfrac{1}{2+y}+\dfrac{1}{2+z} \leq \dfrac{3}{4} \\