Question 11
Find the distinct primes $p, q, r$ and $s$ satisfying
$$
1 - \frac{1}{p} - \frac{1}{q} - \frac{1}{r} - \frac{1}{s} = \frac{1}{pqrs}.
$$
$$
1 - \frac{1}{p} - \frac{1}{q} - \frac{1}{r} - \frac{1}{s} = \frac{1}{pqrs}.
$$
MathNet 2015-part-05 — 191 problems (EN–VI) Question 11
Math Olympiad Vault · MathNet 2015-part-05 — 191 problems (EN–VI)