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MathNet 2019-part-07 — 184 problems (EN–VI) Question 121

Math Olympiad Vault · MathNet 2019-part-07 — 184 problems (EN–VI)

Question 121

Determine all positive $x, y, z$, that satisfy the following system of inequalities:
$$
\begin{cases} (x+1)(y+1) \le (z+1)^2, \\ \left(\frac{1}{x}+1\right)\left(\frac{1}{y}+1\right) \le \left(\frac{1}{z}+1\right)^2. \end{cases}
$$