Page 43 - Math Course 1 (Book 1)

Arithmetic Sequences

Skill Practice!

Determine whether each sequence is an arithmetic sequence. If it is, state the common difference.
EXAMPLE: 1, 3, 5, 7, 9, 11, … is an arithmetic sequence. Justify your answer.
ANSWER: If possible, f nd the common difference between the terms. Since 3 - 1 = 2, 5 - 3 = 2, and so on,
the common difference is 2.
Since the difference between the terms of 1, 3, 5, 7, 9, 11, … is constant, this is an
arithmetic sequence.
GIVEN:
1) 1, 5, 9, 13, 17, … 2) 8, 4, 0, -4, -8, … 3) 1, 3, 9, 27, 81, … 4) 10, 15, 25, 40, 60, …

Find the nth term of each arithmetic sequence described.
1) a1 = 6, d = 3, n = 12 2) a1 = 10, d = -3, n = 15 3) a1 = 8, d = -6, n = 14

Find the next three terms of each arithmetic sequence.
1) 3, 7, 11, 15, … 2) 22, 20, 18, 16, … 3) 19, 24, 29, 34, … 4) 16, 7, -2, -11,
…

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