Verified Answer :

since i=1, 
6(3)^i-1
6(3)^1-1
6(3)^0
6(1)
=6.
:- 6(3)^i-1 = 6

meerkat18

The partial sum can be determined through the calculator or substituting the value to the variable manually. 

6(3)^(1-1) = 6
6(3)^(2-1) = 18
6(3)^(3-1) = 54  
6(3)^(4-1) = 162 
6(3)^(5-1) = 486
6(3)^(6-1) = 1458
6(3)^(7-1) = 4374

total is   6558

Related Questions