Font (2 3) - + Letter spacing (4 5) - + Word spacing (6 7) - + Line spacing (8 9) - +

Binomial expansion

For any positive integer ${n}$

$\displaystyle(p+q)^{n}$	$\displaystyle=$	$\displaystyle(p+q)\ldots(p+q)$
	$\displaystyle=$	$\displaystyle\binom{n}{0}p^{n}q^{0}+\binom{n}{1}p^{n-1}q^{1}+\ldots+\binom{n}{% i}p^{n-i}q^{i}+\ldots+\binom{n}{n}p^{0}q^{n}$
	$\displaystyle=$	$\displaystyle\sum_{i=0}^{n}\binom{n}{i}p^{n-i}q^{i}.$