Answers

2016-07-31T22:15:57+08:00
The answer is 484. An = ar^n-1 324 = 4(3)^n-1 Divide both sides by 4 81 = 3^n-1 81 can also be written as 3^4 3^4=3^n-1 4=n-1 n= 5 a= 4 Sn= (a - ar^n) / (1-r) S5 = [4 - 4(3)^5] / (1-3) S5 = (4 - 4(243)) / (-2) S5 = (4 - 972) / (-2) S5 = (-968) / (-2) S5 = 484
0