9514 1404 393
Answer:
(1, 2), (2, 5), (3, 8), (4, 11), (5, 14)
Explanation:
Put the numbers 1 through 5 in the formula and do the computation:
n = 1 (first term): 2 + 3(1 -1) = 2
n = 2 (second term): 2 + 3(2 -1) = 5
n = 3 (third term): 2 + 3(3 -1) = 8
n = 4 (fourth term): 2 + 3(4 -1) = 11
n = 5 (fifth term): 2 + 3(5 -1) = 14
The first 5 ordered pairs are (n, an) = (1, 2), (2, 5), (3, 8), (4, 11), (5, 14).
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Alternatively, you can compare the given formula to the formula for the general term of an arithmetic sequence:
an = a1 + d(n -1)
Matching features of this formula with the given one, we see that ...
a1 = 2, d = 3
That is, the first term is 2, and the common difference is 3. We can write down the sequence by starting with 2 and counting by 3s from there:
2, 5, 8, 11, 14, 17, 20, 23, ...
Each "ordered pair" will consist of (term number, term value). Then the first 5 ordered pairs are ...
(1, 2), (2, 5), (3, 8), (4, 11), (5, 14)