Jawabanmu

2014-01-19T21:04:58+07:00
A = 2
U4 = a . r^3
1/4 = 2 . r^3
r = 1/2
S6 = 2 + 1 + 1/2 + 1/4 + 1/8 + 1/16
     = 3 15/16