The AM of n numbers of a series is `bar(X). ` If the sum of first (n-1) terms is k, then the `n^(th)` number is

If the sum of the first n terms of the series

The nth term of a series is 3^(n) + 2n , find the sum of first n terms of the series.

The nth term of a series is 3^(n)+2n; find the sum of first n terms of the series.

The nth term of a series is 3^n + 2n ; find the sum of first n terms of the series.

The sum of the first n terms of a series is 31, and the sum of the first n - 1 terms of the series is 20. What is the value of nth terms in the series?

Find the sum to n terms of the series whose n^(th) term is n^2+2^n

Find the sum to n terms of the series whose n^(th) term is n^3-3^n

If n th term of a-series be (2.3^(n-1)+1) ,, find the sum of 1st r terms of the series.