Question

If the number of terms in the expansion of $(a+b{)}^{n^2+3}$ is $7$, then the number of value(s) of $n,(n\in N)$ is

Answer 1

The number of terms is
$n^2+3+1=7\Rightarrow n^2=3\Rightarrow n=\pm \sqrt{3}$
As $n\in N$, so there are no possible values.