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MathNet 2016-part-01 — 184 problems (EN–VI) Question 26

Math Olympiad Vault · MathNet 2016-part-01 — 184 problems (EN–VI)

Question 26

Prove that all real numbers $x \neq -1$, $y \neq -1$ with $xy = 1$ satisfy the following inequality:
$$
\left(\frac{2+x}{1+x}\right)^2 + \left(\frac{2+y}{1+y}\right)^2 \ge \frac{9}{2}
$$