diketahui barisan geometri 27 9 3 1..1/81. banyaknya suku barisan tersebut
Matematika
Dinda01Dinda
Pertanyaan
diketahui barisan geometri 27 9 3 1..1/81. banyaknya suku barisan tersebut
2 Jawaban
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1. Jawaban retnoosay
a=27
r = 1/3
Un = a.r^n-1
1/81 = 27 . 1/3^n-1
1/3^4 = 3^3 . 3^-n+1
3^-4 = 3^4-n
-4 = 4-n
n = 8 -
2. Jawaban ArifinThg
a =27
r =1/3
Un = ar^n-1
1/81 = 27 1/3^n-1
3^-n+1 = 3^-7
n = 8