This isn’t a riddle but a factual question I’ve wondered about:
I’ve heard that Kramer’s Rule (a method of solving a system of x unique linear equations and x unknowns) was developed by the Vilna Gaon (who did, if I understand correctly, have that last name). This is something I’ve only heard/ read in Jewish sources but have never seen this verified. The author of Kramer’s rule is not identified anywhere that I know of, so I suppose it could be the Vilna Gaon, but it seems very unlikely.
Has anyone else found any verifiable source for who actually developed Kramer’s Rule?