MathDB
sum 1/x(1-y ) >= 3 / ( xyz+(1-x)(1-y)(1-z) ) , for 0<x,y,z<1

Source: VI Soros Olympiad 1990-00 R1 9.10 https://artofproblemsolving.com/community/c2416727_soros_olympiad_in_mathematics

May 27, 2024
algebrainequalities

Problem Statement

Let x,y,zx, y, z be real numbers from interval (0,1)(0, 1). Prove that 1x(1y)+1y(1x)+1z(1x)3xyz+(1x)(1y)(1z)\frac{1}{x(1-y)}+\frac{1}{y(1-x)}+\frac{1}{z(1-x)}\ge \frac{3}{xyz+(1-x)(1-y)(1-z)}