Three Absolute Dominations

Problem

Real numbers a,b,ca, b, c satisfy

ab+c,bc+a,ca+b.|a| \geqslant |b + c|, \qquad |b| \geqslant |c + a|, \qquad |c| \geqslant |a + b|.

Prove that a+b+c=0a + b + c = 0.

Answer

Solution

Difficulty7/10
TopicsAbsolute Value, algebra, inequality, Symmetry

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