Question

Find the sum of the first 100 terms of the arithmetic sequence with the first term 2 and the common difference 5.

Answer 1

Answer: 24950

Explanation:

We use the formula

sn=n2(2a+(n−1)d)

To find the sum of the first n terms of an arithmetic series with common difference d (5) and first term a (2).

Sn=100/2(2*2+(100−1)5)

Solving for a we obtain:

Sn=50(4+495)

Sn=50(499) = 24950