You have the following sequence given in the exercise:
You can identify that it is an Arithmetic sequence, because the difference between one term and the previous one is always the same:
By definition, you can express an Arithmetic sequence using a rule:
Where:
- The nth term of the sequence is
- The first term is
- The common difference is "d".
- The term position is "n".
In this case you know that:
Therefore, you can substitute this value into
Then, you get that the answer is: