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5 votes
Find an explicit formula for the arithmetic sequence
81,54,27,0,...

User Yvoytovych
by
2.9k points

2 Answers

2 votes

Answer:

-27n + 108.

Explanation:

-27n + 108.

User Hisham Ahamad
by
3.3k points
6 votes

Answer:

an = -27n + 108.

Explanation:

The first term a1 = 81 and the common difference d = 54-81 = -27 . (Also 27 - 54 = -27 and 0 - 27 = -27).

The explicit formula is

an = a1 + d(n - 1)

= 81 - 27(n - 1)

= -27n + 81 + 27

= -27n + 108.

User Infinity
by
3.6k points