Barisan geometri dengan U3 = 8 dan U5 = 32,tentukan suku pertamanya,rasionya,dan jumlah sembilan suku pertama!

U3= ar^2 = 8
U5 = ar^4 = 32
(ar^2).r^2 = 32
( 8 ).r^2 = 32
r^2 = 32/8 = 4
r = akar 4
r = 2
ar^2 = 8
a(2)^2 = 8
4a = 8
a = 8/4 = 2
Sn = a ( r^n - 1 ) / ( r - 1 )
S9 = 2 ( 2^9 - 1 ) / ( 2-1)
= 2 ( 512 - 1 ) / 1
= 2. 511
= 1.022