Jawabanmu

2014-05-05T23:22:43+07:00
ar^6  = 192
ar³    =  24
  r³    = 8
r = 2
ar³ = 24
a(2)³ = 24
8a = 24
a = 3

U12 = ar^11
       = 3(2)^11
       = 6144