http://www.bing.com:80/search?q=Abba+Then+%26+NowSearch resultshttp://www.bing.com:80/s/a/rsslogo.gifhttp://www.bing.com:80/search?q=Abba+Then+%26+NowCopyright © 2026 Microsoft. All rights reserved. These XML results may not be used, reproduced or transmitted in any manner or for any purpose other than rendering Bing results within an RSS aggregator for your personal, non-commercial use. Any other use of these results requires express written permission from Microsoft Corporation. By accessing this web page or using these results in any manner whatsoever, you agree to be bound by the foregoing restrictions.https://math.stackexchange.com/questions/5121480/if-abba-baab-a-b-show-operatornametra2-operatornametrb2That is, there seems to be fairly strong symbolic evidence that for $n=4$, if $ABBA-BAAB = A-B$ and $A$ is nilpotent, then $B^4 = \lambda I$ for some $\lambda$.Wed, 08 Apr 2026 02:40:00 GMThttps://math.stackexchange.com/questions/895304/how-many-ways-can-we-get-2-as-and-2-bs-from-aabbBecause abab is the same as aabb. I was how to solve these problems with the blank slot method, i.e. _ _ _ _. If I do this manually, it's clear to me the answer is 6, aabb abab abba baba bbaa baab Which is the same as $$\binom {4} {2}$$ But I don't really understand why this is true? How is this supposed to be done without brute forcing the ...Sun, 26 Apr 2026 06:00:00 GMThttps://math.stackexchange.com/questions/1227190/a2-abba-prove-that-detab-ba-0I get the trick. Use the fact that matrices "commute under determinants". +1Sat, 25 Apr 2026 16:03:00 GMThttps://math.stackexchange.com/questions/194956/divisibility-tests-for-palindromesI've found and proven the following extensions to palindromes of the usual divisibility rules for 3 and 9: A palindrome is divisible by 27 if and only if its digit sum is. A palindrome is divisible by 81 if and only if its digit sum is. This doesn't straightforwardly extend to 243. As an example, using this you can immediately see the smallest palindromic multiple of 81 is 999999999, and the ...Wed, 29 Apr 2026 00:06:00 GMThttps://math.stackexchange.com/questions/185457/matrices-conditions-for-abba-0There must be something missing since taking $B$ to be the zero matrix will work for any $A$.Sat, 02 May 2026 00:17:00 GMThttps://math.stackexchange.com/questions/4771478/if-abba-1-and-a3-a-in-a-ring-show-that-a2-1The first condition holds for all $b$ or for some particular $b$?Fri, 24 Apr 2026 08:11:00 GMThttps://math.stackexchange.com/questions/4431053/how-to-calculate-total-combinations-for-aabb-and-abbb-setsAlthough both belong to a much broad combination of N=2 and n=4 (AAAA, ABBA, BBBB...), where order matters and repetition is allowed, both can be rearranged in different ways: First one: AABB, BBAA,Fri, 24 Apr 2026 00:26:00 GMThttps://math.stackexchange.com/questions/4618459/cw-complex-for-m%c3%b6bius-strip-and-its-homeomorfisamsAccording to this question, there is CW complex with one 0-cell,one 1-cell and one 2-cell. No such CW structure exists on the the Möbius strip. Moreover the linked question doesn't claim that, and the answer that claimed that was deleted. It is well known that the Euler characteristic of the Möbius strip is zero. Because given a one $0$ -cell, two $1$ -cells, and one $2$ -cell structure ...Fri, 01 May 2026 10:26:00 GMThttps://math.stackexchange.com/questions/589147/common-factors-for-all-palindromesFor example a palindrome of length $4$ is always divisible by $11$ because palindromes of length $4$ are in the form of: $$\\overline{abba}$$ so it is equal to $$1001a+110b$$ and $1001$ and $110$ areFri, 01 May 2026 19:30:00 GMThttps://math.stackexchange.com/questions/873388/string-functionJane loves string more than anything. She made a function related to the string some days ago and forgot about it. She is now confused about calculating the value of this function. She has a str...Sat, 25 Apr 2026 17:28:00 GMT