## Algebra 2 (1st Edition)

We test the difference of consecutive terms. If it is constant, the sequence is arithmetic. $\left[\begin{array}{llllllllll} n: & 1 & & 2 & & 3 & & 4 & & 5\\ a_{n}: & 5 & & 14 & & 23 & & 32 & & 41\\ diff. & & 14-5=9 & & 23-14=9 & & 32-24=9 & & 41-32=9 & \end{array}\right]$ There is a common difference between consecutive terms, so the sequence is arithmetic.