Answers

2016-07-09T20:18:38+08:00
An=a1r^n-1
2916= 4(3)^n-1
2916/4 = 4/4 (3)^n-1
729 = 3^n-1
3^6 = n-1
6= n-1
6+1 = n
n = 7
0