Source: 2022 Bulgarian Spring Math Competition, Problem 8.3
March 27, 2022
algebraInequalityinequalities
Problem Statement
Given the inequalities:
a)(b+c2a)2+(a+c2b)2+(a+b2c)2≥ca+ab+bcb)(ca+b)2+(ab+c)2+(bc+a)2≥ba+cb+ac+9
For each of them either prove that it holds for all positive real numbers a, b, c or present a counterexample (a,b,c) which doesn't satisfy the inequality.