SOLUTION: The 4th term of an arithmetic sequence is 28 and the 7th term is 43. Find the 79th term.

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Question 1039532: The 4th term of an arithmetic sequence is 28 and the 7th term is 43. Find the 79th term.
Answer by stanbon(75887) About Me  (Show Source):
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The 4th term of an arithmetic sequence is 28 and the 7th term is 43. Find the 79th term.
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a + 3d = 28
a + 6d = 43
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Subtract and solve for "d"::
3d = 15
d = 5
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Solve for "a":
a + 3d = 28
a + 15 = 38
a = 25
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Ans: a(79) = a+78d = 25 + 78*5 = 25 = 350+40 = 398
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Cheers,
Stan H.
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