Given:
The arithmetic sequence is −15, −33, −51, −69.
To find:
The nth term of the arithmetic sequence.
Solution:
We have,
−15, −33, −51, −69
Here,
First term: a = -15
Common difference is
[tex]d = -33-(-15)[/tex]
[tex]d = -33+15[/tex]
[tex]d = -18[/tex]
Now, nth term of an arithmetic sequence is
[tex]a_n=a+(n-1)d[/tex]
Substitute a=-15 and d=-18.
[tex]a_n=-15+(n-1)(-18)[/tex]
[tex]a_n=-15-18n+18[/tex]
[tex]a_n=-18n+3[/tex]
Therefore, the nth term of the given arithmetic sequence is [tex]a_n=-18n+3[/tex].
