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Natasha_Volkova [10]
3 years ago
15

what is the sum of the first 5 terms if of a geometric series with a1=20 and r=1/4 the answer has to be an improper fraction

Mathematics
1 answer:
amm18123 years ago
3 0
The sum of the term in a geometric sequence
Sn=\frac{a1(1-r^n)}{1-r}
where
there are n terms
r is common ratio
a1 is first term

Sn=\frac{20(1-(1/4)^5)}{1-(1/4)}
Sn=\frac{20(1-(1/1024))}{3/4}
Sn=\frac{20(1023/1024)}{3/4}
Sn=\frac{1705}{64}


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Step-by-step explanation:

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\bf \begin{array}{clclll}
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\\\\\\
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Step-by-step explanation:

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