The nth term of a series is 2^n-1 +5n. Find the sum of the first n terms.

Question

(Hint: This is an expression in terms of n).

Answer 1

well, the first n terms of 2^(n-1) is 2^n - 1

The first n terms of 5n is 5 * n(n+1)/2

So, the sum you want is

2^n - 1 + 5n(n+1)/2