SOLUTION: the 5th and 10th terms of an AP are -12 and -27 respectively. find the AP and is 15th term

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Question 977799: the 5th and 10th terms of an AP are -12 and -27 respectively. find the AP and is 15th term









Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
the 5th and 10th terms of an AP are -12 and -27 respectively.
find the AP and its 15th term.
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a(5) = a(1)+4d = -12
a(10) = a(1)+9d = -27
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Subrract and solve for "d"::
5d = -15
d = -3
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Solve for a(1)::
a(1) + 4d = a(1)-12 = -12
a(1) = 0
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Cheers,
Stan H.
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