PLEASE HELP EASY ALGEBRA

What is the sum of the geometric sequence 1, 3, 9, … if there are 10 terms?
A: 29,524
B: 55,987
C: 87,381
D: 88,573

Respuesta :

The terms of the geometric sequence are 1,3,9, ...,

The first term is a = 1
The common ratio is r = 3.

The sum of the first 10 terms is


Answer:  29524

Answer: Option 'A' is correct.

Step-by-step explanation:

Since we have given that

Geometric series is as follows:

1,3,9,................

Number of terms = 10

n = 10

a = 1

r = [tex]\dfrac{a_2}{a_1}=\dfrac{3}{1}=3[/tex]

We need to find the sum of the geometric sequence for 10 terms.

[tex]S_{10}=\dfrac{a(r^n-1}{r-1}\\\\S_{10}=\dfrac{1(3^{10}-1)}{3-1}\\\\S_{10}=\dfrac{59048}{2}\\\\S_{10}=29,524[/tex]

Hence, Option 'A' is correct.