Answer:
a(31) = 84
Explanation:
The first term, a(1) is 204, and the common difference is 4. That is, each new term is 4 less than the previous term.
The rule governing this arithmetic sequence is
a(n) = 204 - 4(n - 1)
and so the 31st term is
a(31) = 204 - 4(30) = 84