Question 181
Find all triples $(a, b, c)$ of nonnegative integers that satisfy
$$
a! + 5^{b} = 7^{c}
$$
$$
a! + 5^{b} = 7^{c}
$$
MathNet 2019-part-03 — 184 problems (EN–VI) Question 181
Math Olympiad Vault · MathNet 2019-part-03 — 184 problems (EN–VI)