# If an arithmetic sequence has a 1st term of 3 and a 10th term of 21, what is the sum of the first...

## Question:

If an arithmetic sequence has a 1st term of 3 and a 10th term of 21, what is the sum of the first 10 terms?

## Arithmetic Succession:

An arithmetic sequence is characterized because the difference between one term and the previous one remains constant (called common difference). There is a pattern, so that the terms, starting from the second, are obtained by adding the common difference to the previous term.

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Data

{eq}a_1=3 \\ a_{10}=21 \\ n=10 \, \text{terms} {/eq}

The Sum of terms of an arithmetic sequence is given by the formula

{eq}S_n=\dfrac{a_...