How can you get the common difference in an arithmetic sequence?

Answer 1

You subtract any two adjacent numbers in the sequence. For example, in the sequence (1, 4, 7, 10, ...), you can subtract 4 - 1, or 7 - 4, or 10 - 7; in any case you will get 3, which is the common difference.

Answer 2

In an arithmetic sequence the common difference is the same between any two terms, so to get the common difference subtract any one term from the term following it.

Answer 3

Take any number in the sequence (other than the first) and, from it, subtract the number before it.