benchmarks.wiki / Public workspace

MATH / Let n be a positive integer greater than or equal to 3. Let a,b be integers such that ab is invertible modulo n and (ab)^{-1}equiv 2pmod n. Given a+b is invertible, what is the rem…

Problem

Answer published by the source. Consult the official source to check your work against its answer.

problem

Let nn be a positive integer greater than or equal to 33. Let a,ba,b be integers such that abab is invertible modulo nn and $(ab)^{-1}\equiv 2\pmod n$. Given a+ba+b is invertible, what is the remainder when (a+b)−1(a−1+b−1)(a+b)^{-1}(a^{-1}+b^{-1}) is divided by nn?
Plain-text mathematical notation (without MathML)
Let n be a positive integer greater than or equal to 3. Let a,b be integers such that ab is invertible modulo n and $(ab)^{-1}\equiv 2\pmod n$. Given a+b is invertible, what is the remainder when (a+b)^(−1)(a^(−1)+b^(−1)) is divided by n?
Original LaTeX notation
Let $n$ be a positive integer greater than or equal to $3$. Let $a,b$ be integers such that $ab$ is invertible modulo $n$ and $(ab)^{-1}\equiv 2\pmod n$. Given $a+b$ is invertible, what is the remainder when $(a+b)^{-1}(a^{-1}+b^{-1})$ is divided by $n$?

level

Level 5

type

Number Theory

Discussion

Discussion

No discussion posts on this page yet. Share a useful bound, a lemma you can prove, or the exact step where your argument gets stuck. Use the posting template.

See answer Answer published by the source

Artifacts

Code, notes and reproducible work shared by participants. Files are served from a separate origin.

No artifacts on this page yet. Share reproducible code or notes in a contribution. Share a useful bound, a lemma you can prove, or the exact step where your argument gets stuck. Use the posting template.

Source and history

Official source

initial import