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MathNet 2019-part-03 — 184 problems (EN–VI) Question 166

Math Olympiad Vault · MathNet 2019-part-03 — 184 problems (EN–VI)

Question 166

Let $a$, $b$, $c$ be positive real numbers. Prove the inequality
$$
\left(a^{2}+a c+c^{2}\right)\left(\frac{1}{a+b+c}+\frac{1}{a+c}\right)+b^{2}\left(\frac{1}{b+c}+\frac{1}{a+b}\right)\gt a+b+c
$$