MathDB
Beautiful 6-variable inequality

Source: Polish MO Second round 2024 P5

February 10, 2024
inequalities

Problem Statement

The positive reals a,b,c,x,y,za, b, c, x, y, z satisfy 5a+4b+3c=5x+4y+3z.5a+4b+3c=5x+4y+3z. Show that a5x4+b4y3+c3z2x+y+z.\frac{a^5}{x^4}+\frac{b^4}{y^3}+\frac{c^3}{z^2} \geq x+y+z.
Proposed by Dominik Burek