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MathNet 2018-part-02 — 181 problems (EN–VI) Question 9

Math Olympiad Vault · MathNet 2018-part-02 — 181 problems (EN–VI)

Question 9

Let $a$, $b$ and $c$ be positive real numbers such that $a + b + c = 2$. Prove that
$$
\frac{(a-1)^2}{b} + \frac{(b-1)^2}{c} + \frac{(c-1)^2}{a} \ge \frac{1}{4} \left( \frac{a^2+b^2}{a+b} + \frac{b^2+c^2}{b+c} + \frac{c^2+a^2}{c+a} \right).
$$