Question 85
Determine all triples $(a, b, c)$ of positive integers for which $a b - c$, $b c - a$, and $c a - b$ are powers of $2$.
Explanation: A power of $2$ is an integer of the form $2^{n}$, where $n$ denotes some nonnegative integer.
Explanation: A power of $2$ is an integer of the form $2^{n}$, where $n$ denotes some nonnegative integer.