MathDB
An inequality problem from China TST

Source: 2017 China TST 4 Problem 5

March 22, 2017
inequalitiesTST

Problem Statement

Given integer m2m\geq2,x1,...,xmx_1,...,x_m are non-negative real numbers,prove that:(m1)m1(x1m+...+xmm)(x1+...+xm)mmmx1...xm(m-1)^{m-1}(x_1^m+...+x_m^m)\geq(x_1+...+x_m)^m-m^mx_1...x_mand please find out when the equality holds.