Chapter 9 - Sequences and Series - 9-2 Arithmetic Sequences - Practice and Problem-Solving Exercises - Page 575: 7

Arithmetic sequence with a common difference of $10$.

You are given the sequence $10,20,30,40$. Check to see if there is a common difference (the difference between consecutive terms) and if there is,the sequence would be arithmetic: Note that $20-10=10\\ 30-20=10\\ 40-30=10$ The difference is $10$ which is a common difference so the given sequence is arithmetic.