The binomial theorem describes the algebraic expansion of powers of a binomial. According to the theorem, it is possible to expand the power (x+y)n into a sum involving terms of the form axbyc. The coefficient a is called binomial coefficient.
The coefficients of the expansions are arranged in an array. This array is called Pascal’s triangle.
General Term of Expansion (a+b)n
Tr+1 = nCr an–r. br
Number of Terms
Number of terms in expression of (x+y)n or (x-y)n is n+1.