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finlep [7]
2 years ago
15

In an AP, the 8th term is equal to the sum of the first 8 terms. Show that the 4th term is 0

Mathematics
1 answer:
dimulka [17.4K]2 years ago
5 0

Answer:

let the first term of an A.P. is 'a' and common difference 'd'

∴ 8th term = sum of the first 8 terms

a8 = S

a + 7d = 8/2(2a + (8 - 1)d)

a + 7d = 8/2(2a + 7d)

2a + 14d = 16a + 56d

16a + 56d - (2a + 14d) = 0

14a + 52d = 0

divide eq. by 14 we get  ,

a + 3d = 0

and a + 3d = a4  = 0

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