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प्रश्न
For the G.P. if r = − 3 and t6 = 1701, find a.
उत्तर
tn = arn−1, where r = − 3
∴ t6 = a(−3)6 −1 = 1701
∴ a(− 3)5 = 1701
∴ − 243a = 1701
∴ a = `(1701)/(-243)`
= − 7
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