Binomial Expansion with Three Terms

Binomial Expansion with Three Terms

## Formula

For:

$$(a+b+c)^n$$

the multinomial expansion is:

$$(a+b+c)^n=\sum_{p+q+r=n}\frac{n!}{p!q!r!}a^pb^qc^r$$

where:

$$p,q,r\ge0$$

## Usage

- Used when a power of a trinomial or three-variable expression must be expanded or a particular term must be found.