Q23 of 25 Page 8

In the expansions of (1 + a)m+n, using Binomial Theorem, prove that coefficients of am and an are equal.


We have,

(1 + a)m+n = [m+nC0 + m+nC1a1 + m+nC2a2+…… m+nCr

ar + …… + m+nCm+n am+n

Coefficient of am = m+nCm =

Also the coefficient of an

= m+nCn =

Clearly, m+nCm = m+nCn

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