diketahui deret geometri 45+15+5+..... tentukan S10?
Matematika
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Pertanyaan
diketahui deret geometri 45+15+5+..... tentukan S10?
1 Jawaban
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1. Jawaban dikisiswanto
a = 45
r = 15/45 = 1/3
S10 = a . (1 - r^9)/(1-r)
S10 = 45 . (1 - 1/3^9 / (1 - 1/3)
S10 = 45 . ( 19682/19683) / 2/3
S10 = 45 .(19682/19683) × 3/2
S10 = (45 × 19682 × 3)/(19683×2)
S10 = 67,5