# A number theory problem by Vishnu Kadiri

Number Theory Level 3

$\large {\begin{cases} pq = r+1 \\ 2(p^2 + q^2) = r^2 + 1 \end{cases} }$

Let $$p,q$$ and $$r$$ be prime numbers satisfying the system of equations above.

Find $$r$$.

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