The Binomial Theorem: Formulas

The formal expression of the Binomial Theorem is as follows:

(a + b)n = Σ

(

n k

)

an − k bk

with

(

n k

)

=

nck

=

n! (n−k)!·k!

(often called "n, choose k")

The factorial notation "n!" means " the product of all the whole numbers between 1 and n".