Question

can u plz tell me the binomial formula.

Answer 1

\[ (a + b)^n = \sum_{r = 0}^n \binom{n}{r}a^{n - r} b^r\]

Answer 2

y u no google

Answer 3

http://lmgtfy.com/?q=binomial+theorem+

Answer 4

combination coefficients get involved because you can pick r a's from n (a+b)'s in
nCr ways.