SOLUTION: a question on the homework i have says: Let the sum of an arithmetic sequence of eight terms be represented by the letter S. If the first term is "a" and the eighth term is "a/2" e

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Question 388365: a question on the homework i have says: Let the sum of an arithmetic sequence of eight terms be represented by the letter S. If the first term is "a" and the eighth term is "a/2" express "a" as a function of S.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
a question on the homework i have says: Let the sum of an arithmetic sequence of eight terms be represented by the letter S.
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If the first term is "a" and the eighth term is "a/2" express "a" as a function of S.
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a(8) = a + 7d = a/2
7d = -a/2
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S(8) = (8/2)(a+a+7d) = 4(2a+7d)
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S(8) = 4(2a-(a/2))
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S(8) = 4(3/2)a)
S(8) = 6a
a = (1/6)*S(8)
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Cheers,
Stan H.