duplicates $7\mid 3^{2n+1}+2^{n+2}$ seems to be rather frequent question (recently I have noticed one copy in the HNQ). Approach0, SearchOnMath.

233937: Prove $3^{2n+1} + 2^{n+2}$ is divisible by $7$ for all $n\ge0$, 810063: Show that $7\mid(3^{2n+1}+2^{n+2})$ for all $n\in\mathbb{N}$, 1286522: How to prove that $2^{n+2}+3^{2n+1}$ is divisible by 7 using induction?, 1604280: Find all $n$ such that $3^{2n+1}+2^{n+2}$ is divisible by $7$

2427747: Prove by induction: $2^{n+2} +3^{2n+1}$ is divisible by $7$ for all $n \in \mathbb{N}$, 2681223: Prove that $3^{2n-1} + 2^{n+1}$ is always a multiple of $7$., 3795659: Prove that the number $3^{2n+1}+2^{n+2}$ is divisible by $7$

[ SmokeDetector | MS ] Post is mostly images (12): Evaluate (without long way) by Sujee Sujee Sujee on math.SE

@user21820 Sorry to not reply earlier, but there is now a policy in place.

@r.e.s. There is an argument to be made that a lack of mathematical maturity or sophistication is an indicator of the asker's ability, which should inform the level to which an answer should be aimed. Thus, in general, editing a post to use more advanced notation or phrasing is not a good idea.

That being said, in this case, the asker left a comment indicating that the edits were, in fact, in alignment with their intent. As such, I don't see a problem with the edit.

Of course, I do understand @amWhy's objection: the timeline makes it look like @r.e.s. answered the question in a way that was not quite right, then edited the question to make it better fit their answer. This doesn't look good.

@amWhy If @r.e.s. had first edited the question, then gotten confirmation from the asker that the edit was okay, and only then answered the question, would you have found that acceptable?

cv-pls optimization PSQ with expired bounty. If $\min_x \max_y: f(x,y)$ is convex and concave saddle point problem, is this correct $\min_x \max_y: f(x,y) = \max_x \min_y: -f(x,y)$?‭ - E.J.‭ 2020-08-07 20:00:46Z

@XanderHenderson I still get a message telling me that the question has an open bounty, so it can't be closed yet.

DA, DB, DC, DD, DE, DF, DG, DH

DI, DJ, DK, DL

@XanderHenderson: thanks (mod team) for taking time to formulate the policy. On the face of it the policy may not look so appealing to those who want to preserve the nice answers (because there is reasonable effort involved), but doing this will actually help them to focus on gems rather the routine stuff and in a way it is about using their resources economically.

@ParamanandSingh I concur, @ParamanandSingh. Thanks to the mod team for their careful consideration and construction of the policy.

D1, D2, D3.

D4, D5, D6.

D7, D8, D9.

D10, D11, D12.

@XanderHenderson Thanks!

Deleted and now undeleted: DI

[ SmokeDetector | MS ] Potentially bad keyword in body, potentially bad keyword in title, blacklisted user (73): The Stepladder Proof of The Goldbach Conjecture on Academia.edu by GREGORY MAZUR on math.SE

[ SmokeDetector | MS ] Potentially bad keyword in body, potentially bad keyword in title, blacklisted user (73): The Stepladder Proof of The Goldbach Conjecture on Academia.edu ✏️ by GREGORY MAZUR on math.SE

[ SmokeDetector | MS ] Potentially bad keyword in answer, blacklisted user (72): The Stepladder Proof of The Goldbach Conjecture on Academia.edu by GREGORY MAZUR on math.SE

A completely wrong answer worthy of deletion: math.stackexchange.com/a/3796250

@KReiser gone