In this case, we'll have to carry out several steps to find the solution.
Step 01:
arithmetic sequence
an=-3n+9
a(30) = ?
Step 02:
arithmetic sequence
n = 30
a(30) = -3 (30) + 9
= -90 + 9
= - 81
The answer is:
The term number 30 in the arithemetric sequence is - 81