How do you determine whether the sequence #10, 8, 6, 4, 2,...# is arithmetic and if it is, what is the common difference?
common difference is
A sequence is arithmetic if the difference between consecutive terms is constant.
That is you add or subtract the same number to get the next term
In this case we have:
the differences between each terms are
the differences are all the same so it is an Arithmetic sequence
the common difference is