Answer:
Sum of finite geometric sequence is - 216 .
Explanation:
Given : expression -2(5)n - 1.
To find : Find the sum of a finite geometric sequence from n = 1 to n = 6.
Solution : We have given expression
-2 (5) n - 1.
For n = 1
-2(5) 1 -1
-10 -1 = - 11.
For n = 2
-2(5) 2 -1
-20 -1 = -21.
For n = 3
-2(5) 3 -1.
-30 -1
-31.
For n = 4
-2(5) 4 -1
-40 - 1
-41.
For n = 5
-2(5) 5 -1.
-50 -1
-51.
For n = 6
-2(5) 6 -1
-60 - 1
-61 .
Sum of finite geometric sequence : -11 + (-21) + (-31) + (-41) + (-51) + (-61) .
-11 -21 -31 -41 -51 - 61 .
= -216.
Therefore, Sum of finite geometric sequence is - 216 .