3+9+27+... tentukan A:U6 B:S6
Matematika
satria550
Pertanyaan
3+9+27+... tentukan A:U6 B:S6
2 Jawaban
-
1. Jawaban eripane05
r = 9/3 = 3
U6
= ar^5
= 3 (3^5)
= 3^6
= 729
S6
= a (1-r^n) / 1-r
= 3(1-3^6)/ 1-3
= 3(-728)/-2
= 3(364)
= 1092 -
2. Jawaban BSunShine
Materi : Barisan dan Deret
Kelas : IX SMP
3 + 9 + 27 + .... + ....
r = 3
a = 3
Un = a.r^(n-1)
U6 = 3 . 3^(6-1)
U6 = 3 . 3^5
U6 = 3^6
U6 = 729
Sn = a (1 - r^n ) / 1 - r
S6 = 3(1 - 3^6) / 1 - 3
S6 = 3(1 - 729) / -2
S6 = 3(-728) / -2
S6 = -2184/-2
S6 = 1092