Math.

Factorial:

n! = 1 * 2 * 3 ... (n-1) * n
n! = (n - 1)! * n
0! = 1

Exponentiation:

a^m * aⁿ = a^{m + n}
a^m : bⁿ = a ^{m - n}
(a^m)ⁿ = a^{m * n}
(a * b)^m = a^m * b^m
(a : b)^m = a^m : b^m