Jumlah 10 suku pertama dari 1/3+1/9+1/37+1/81

Kelas 8 Matematika
Bab Barisan dan Deret Bilangan

r = U2 : U1
r = 1/9 : 1/3
r = 1/9 . 3/1
r = 1/3

Sn = a . (1 - rⁿ) / (1 - r)
S10 = 1/3 . (1 - (1/3)¹⁰) / (3/3 - 1/3)
S10 = 1/3 . (59.049/59.049 - 1/59.049) . 3/2
S10 = (59.048/59.049) . 1/2
S10 = 29.524/59.049