21:24

A long road to the limit

17:08

Solving a Quartic Equation

21:39

a * b = ab + a + b

14:57

Find the closest integer

16:43

A Vieta Problem

17:08

n^4 + 3n^2 + 2 is never a perfect square

20:56

Find all integer solutions (Russian Math Olympiad)

24:00

The Subfactorial is Hilarious