Respuesta :

Answer:

280

Step-by-step explanation:

Use the formula: (a((r^n)-1))/(r-1)

= (7((3^4)-1))/(3-1)

The sum of the given geometric series is 280.

We have given that,

a1=7, n=4 and r=3

We have to determine the sum of a geometric series

What is the formula sum of the geometric series?

[tex]S_n=(a((r^n)-1))/(r-1)[/tex]

[tex]= (7((3^4)-1))/(3-1)[/tex]

[tex]=280[/tex]

Therefore the sum of the given geometric series is 280.

To learn more about the geometric series visit:

https://brainly.com/question/25630111

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