Use the Formula for the Sum of the First n Terms of a Geometric Sequence
-Find the sum of the first 9 terms of the geometric sequence: 3, 9, 27, 81, 243, . . . .
A)29,523
B)29,503
C)29,560
D)29,525

Question

Quizplus · Accepted Answer

The first term (a) is 3, the common ratio (r) is 3, and the number of terms (n) is 9. Using the formula for the sum of the first n terms of a geometric sequence, S_n = a(1-r^n)/(1-r), we get S_9 = 3(1-3^9)/(1-3) = 29,523.

Use the Formula for the Sum of the First N