Question

if the 8th term of an ap is the geometric mean of first and 22nd terms of the same find the common difference of the AP given that the sum of the first and 22 terms of the ap is 770
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Answer 1

Answer:

59

Explanation:

lm not sure about the answer l have given

Answer 2

Answer:

d=2

Explanation:

S(22) =770 - (i)

[a(8)^2] = a[a(22)] - (ii)

from (i) by using formula for sum of AP, we have

a = (70-21d)/2 - (iii)

and from (ii) using formula of nth term, we have

7d-a=0 - (iv)

putting value of a from (iii) in (iv)

we will get, d=2.