Explain how to find the sum of the first n terms of an arithmetic series.

To find the sum of the first n terms of an arithmetic series, use the formula Sn = n/2(2a + (n-1)d).

An arithmetic series is a sequence of numbers where each term is the sum of the previous term and a constant difference, called the common difference. For example, the sequence 2, 5, 8, 11, 14 is an arithmetic series with a common difference of 3.

To find the sum of the first n terms of an arithmetic series, use the formula Sn = n/2(2a + (n-1)d), where Sn is the sum of the first n terms, a is the first term, d is the common difference, and n is the number of terms.

For example, to find the sum of the first 10 terms of the arithmetic series 2, 5, 8, 11, 14, we first need to find a and d. In this case, a = 2 and d = 3. Then we can use the formula Sn = 10/2(2(2) + (10-1)3) = 10/2(4 + 27) = 10/2(31) = 155.

Therefore, the sum of the first 10 terms of the arithmetic series 2, 5, 8, 11, 14 is 155.