Question

the ratio of sum of first 4 terms to first 8 term is 81:97 find a, r, s4​

Answer 1

Answer:

Assuming that S8 means Sum(8), and you are dealing with a geometric sequence .....

( a(r^8 - 1)/(r-1) ) / ( a(r^4 - 1)/(r-1) ) = 97/81

(r^8 - 1)/(r^4 - 1) = 97/81

(r^4 - 1)(r^4 + 1)/(r^4-1) = 97/81

r^4 + 1 = 97/81

r^4 = 16/81

r = ± 2/3

Answer 2

Answer:

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Step-by-step explanation:

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