Mathematics

Problem

Identify the expression for the

(r+1)

th term in the expansion of

(a+b)^n

. a)

\displaystyle \binom{n}{r} a^{r} b^{n-r}

\displaystyle \binom{n}{r+1} a^{n-r} b^{r+1}

\displaystyle \binom{n}{r} a^{n-r} b^{r}

\displaystyle \binom{n}{r-1} a^{n-r+1} b^{r-1}