Answer
There is a common difference between consecutive terms (d=9),
so the sequence is arithmetic.
Work Step by Step
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.
