Answer to Question #16729 in Abstract Algebra for john.george.milnor
For any ring k, let A = Mn(k) and let R (resp. S) denote the ring of n × n upper (resp. lower) triangular matrices over k. Show that R, S, R^op, S^op are all isomorphic.
The answer to the question is available in the PDF file https://www.assignmentexpert.com/homework-answers/mathematics-answer-16729.pdf