dik deret geometri 6+2+2/3+3/9+,,,,,,,, tentukan a. r b.s8

Bab Barisan dan Deret
Matematika SMP Kelas IX

1] r = U2 / U1
r = 2/6
r = 1/3

2] Sn = a x (1 - rⁿ) / (1- r)
S8 = 6 x (1 - (1/3)⁸) / (1 - 1/3)
S8 = 6 x (1 - 1/6.561) / (2/3)
S8 = 6 (6.561 - 1)/6.561 x 3/2
S8 = 9 x 6.560/6.561
S8 = 6.560/729
S8 = 8 728/729

r = U2/U1
r = 2/6
r = 1/3

Sn = a(1 - r^n) / ( 1 - n)
S8 = 6(1 - (1/3)^8 / ( 1 - 3)
S8 = 6( 1 - 1/6561) / 2/3
S8 = 6(6560/6561) × 3/2
S8 = 9(6560/6561)
S8 = 8 728/729