Question 4
Find all pairs of primes $(p,q)$ for which $p-q$ and $pq-q$ are both perfect squares.
Proposed by Holden Mui. Source: Evan Chen’s third-party solution notes; https://aops.com/community/p24774670. One point is a nonofficial editorial normalization; this essay requires manual grading.
Proposed by Holden Mui. Source: Evan Chen’s third-party solution notes; https://aops.com/community/p24774670. One point is a nonofficial editorial normalization; this essay requires manual grading.