Question

U3 deret geometri =48
U6 = 384
tentukanlah jumlah 5 suku pertama?
Kalo bisa pakek pecehan bersusun yaahh tolong:)

Answer 1

R^6-3 = 384
           48
r^3 = 8
r = 2

U3 = ar^2 = 48
       a x 2^2 = 48
       a = 48/4
       a=12

Sn= a(r^n - 10)/r-1
S5= 12(2^5 - 1)/ 2 - 1
S5= 12 (32-1)/1
S5=12 x 31
S5 = 372

Answer 2

r^6-3 = 384
           48
r^3 = 8
r = 2

U3 = ar^2 = 48
       a x 2^2 = 48
       a = 48/4
       a=12

Sn= a(r^n - 10)/r-1
S5= 12(2^5 - 1)/ 2 - 1
S5= 12 (32-1)/1
S5=12 x 31
S5 = 372
terima kaih