Mapel: Matematika
Bab: Barisan Geometri
U5 = 48
U9 = 768
Pertama, cari rasio terlebih dahulu
r^(9 – 5) = 768/48
r^4 = 16
r = 2
Kedua, cari suku pertamanya
U5 = a .r^4
48 = a. 2^4
a = 48/16
a = 3
Ketiga, cari suku ke 7
U7 = a.r^6
= 3.2^6
= 3.64
= 192
Jadi, suku ke 7 adalah 192
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Mapel: Matematika
Bab: Barisan Geometri
Pembahasan
U5 = 48
U9 = 768
Pertama, cari rasio terlebih dahulu
r^(9 – 5) = 768/48
r^4 = 16
r = 2
Kedua, cari suku pertamanya
U5 = a .r^4
48 = a. 2^4
a = 48/16
a = 3
Ketiga, cari suku ke 7
U7 = a.r^6
= 3.2^6
= 3.64
= 192
Jadi, suku ke 7 adalah 192
Un = arⁿ-¹
U5 = ar⁴
U9 = ar^8
ar⁴ = 48
a(2)⁴ = 48
a(16) = 48
a = 3
U7 = ar^6
U7 = 3(2)^6
U7 = 3 × 64 = 192