Question 211762
1/125, 1/25, 1/5.....to 7term 
• Write the next 3 terms,
Multiply by 5 to get 1,5,25
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• Find the indicated tn,
t(n) = 5^(n-4)
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• Find the indicated Sn.
S(n)= [5^(n+1)-1]/(5-1)
The n was not specified so the sum is not determined.
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Cheers,
Stan H.