# Binomial Theorem

## Binomial theorem for positive integers

The binomial theorem for positive integers can be expressed as

(x + y)^{n}= x^{n}+ n x^{n-1 }y + n ((n - 1) / 2!) x^{n-2}y^{2}+ n ((n - 1)(n - 2) / 3!) x^{n-3}y^{3}+ .... + n x y^{n-1}+ y^{n}(1)

In mathematics the binomial theorem is important as an equation for expansion of powers of sums.