Question

8.Pada barisan geometri 5, 15, 45, 135, ... Berapakah jumlah 6 suku pertama? ​

Answer 1

Jawaban :

r = 3

a = 5

Sn = a(r pangkat n - 1)/ r - 1

S6 = 5(3⁶ - 1)/3 - 1

S6 = 5(729-1)2

S6 = 5(728)/2

S6 = 3.640/2

S6 = 1.820

Answer 2

CARA JAWABAN

8.)

rasio/r = 3.

Sn = a . (r^n - 1)/(r - 1)

S6 = 5 . (3^6- 1)/(3 - 1)

S6 = 5 . (729-1)/2

S6 = 5 . 728/2

S6 = 3.640/2

S6 = 1.820

Jadi jumlah 6 suku pertama adalah 1.820