Arithmetic sequence are sequence such that the difference between two successive terms are constant.
The constant difference between the successive terms is called the common difference.
An example of Arithmetic sequence is;
The nth term of an arithemetic sequence can be calculated using the formula;
where;
a = first term
d = common difference
Given the sequence;
the first term is 15.
the difference between successive terms is;
common difference d is equal to -7.
Therefore, the given sequence is an arithmetic sequence.