SOLUTION: The first three terms of an arithmetic sequence are -12, -4, and 4. Which term is 212 ?

Question 1044785: The first three terms of an arithmetic sequence are -12, -4, and 4. Which term is 212 ?
Found 3 solutions by Alan3354, ikleyn, MathTherapy:
Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
The first three terms of an arithmetic sequence are -12, -4, and 4. Which term is 212 ?
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Term n = -12 + 8*(n-1)
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Term 1 = -12
Term 2 = -4
Term 3 = +4
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Term 212 = -12 + 8*211 = 1676

Answer by ikleyn(52788)   (Show Source): You can put this solution on YOUR website!
.
The first three terms of an arithmetic sequence are -12, -4, and 4. Which term is 212 ?
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212 = -12 + 8*(n-1). (1) You are asked to find n. From (1) n-1 = = 28. Hence, n = 28 + 1 = 29. Check. -12 + 8*(29-1) = -12 + 8*28 = 212. Correct ! Answer. 212 is the 29-th term.

Answer by MathTherapy(10552)   (Show Source): You can put this solution on YOUR website!
The first three terms of an arithmetic sequence are -12, -4, and 4. Which term is 212 ?

is 212.
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