# Arithmetic series

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##### Examples

###### Lessons

**Arithmetic series formula**

Determine the sum of the first ten terms of the arithmetic series: 6 + 1 – 4 – 9 – … .**Problem involving both arithmetic sequence formula and arithmetic series formula**

Find the sum of the arithmetic series: – 4 – 1 + 2 + …. + 329.**$t_{n}=s_{n}-s_{n-1}$**

The sum of the first n terms of an arithmetic series is ${s_n} = 7{n^2} - 5n$ .- A triangle has a perimeter of 32m; the shortest side is 6 m long. If the side lengths of this triangle form an arithmetic sequence, what are the other side lengths?