The summation notation for the geometric series will be expressed as [tex]\sum5(-2)^{n-1}\\[/tex]
Series are sum of sequences
Given the following alternating series as shown:
5 - 10 + 20 - 40 + 80
The series is geometrc series with the following parameters
First term "a" =5
ratio= -10/5 = 20/-10 = -2
Since the nth term of geometric sequence is expressed as:
Tn = ar^n-1
Tn =5(-2)^n-1
Hence the summation notation for the geometric series will be expressed as [tex]\sum5(-2)^{n-1}\\[/tex]
Learn more on geometric series here: https://brainly.com/question/24643676
