Answer
arithmetic sequence
common difference = $-11$
Work Step by Step
You are given the sequence $97,86,75,64$.
Check to see if there is a common difference (the difference between consecutive terms) and if there is, the sequence would be arithmetic:
Here, we have:
$86-97=-11\\
75-86=-11\\
64-75=-11$
The difference is $-11$, which is a common difference, so the sequence is arithmetic.