If the coefficients of a ^ m and a ^ n in the expansion of (1+a)^ m + n are and , then which one of the following is correct?

Step-by-step solution

aligned & (1+a)^ m+n & = coefficient of a^m= ^ m+n C_m & = coefficient of a^n= ^ m+n C_n aligned We know, ^ n C _ r = ^ n C _ n - r aligned & = ^ m+n C_n= m+n m+n-n = ^ m+n C_m= & = aligned