# Math

The 9th term of an arithmetic progression is three times the 5th term, find the relationship between the first term and common difference

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1. 9th term = a+8d
5th term = a + 4d

given: 9th term = 3(5th term)
a + 8d = 3(a + 4d)
a + 8d = 3a + 12d
-2a = 4d
a = -2d, where a is the first term

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Reiny
2. Do we need to solve for difference
(d)

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