And now for the solution reveal!
Here's the solution to "Factorising Quadratics":
I was fascinated by how many 10-letter mathematicians there are: for example, Pythagorus, Fibbonacci, Archimedes, Von Neumann and Alan Turing were names I could see as meta submissions. However, there was a good reason for the answer being DIOPHANTUS.
From
Wikipedia:
"Most of the problems in
Arithmetica lead to quadratic equations. Diophantus looked at 3 different types of quadratic equations: ax2 + bx = c, ax2 = bx + c, and ax2 + c = bx. The reason why there were three cases to Diophantus, while today we have only one case, is that he did not have any notion for zero and he avoided negative coefficients by considering the given numbers a, b, c to all be positive in each of the three cases above."
The 5 equations encoded into the puzzle all fit Diophantus' first case. However, by using algebraic notation (rather than a purely geometric method) and factorising as shown, we can go beyond Diophantus by recognising that these equations also have negative solutions.
Interestingly, if you've heard of "Fermat's Last Theorem", Pierre de Fermat wrote this in the margin of a copy of Diophantus' book. Special shoutout, therefore, to @merlinnimue who commented on Crosshare: "I have discovered a truly remarkable solution to this meta puzzle, but unfortunately this text field is too small to contain it." Love it!