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VTMO 2026 - Grade 9 - Final - SET 9 - Self-study Question 5

VTMO · VTMO 2026 - Grade 9 - Final - SET 9 - Self-study

Question 5

Let $a,b$ be positive odd integers satisfying $b\mid a^2+2$ and $a\mid b^2+2$.

a) Prove $ab\mid a^2+b^2+2$.

b) Prove that $\dfrac{a^2+b^2+2}{ab}$ is a perfect square.