Tentukan jumlah 6 suku pertama deret geometri berikut 16 + 4 + 1 +….

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Tentukan jumlah 6 suku pertama deret geometri berikut
16 + 4 + 1 +….

Un=ar^n-1

a = U1 = 16

r = rasio = U2/U1= 4/16=1/4

S6= a. (1-r^n) /(1-r)

= 16.(1-(1/4)^6)/(1-1/4)

=16.(1-(1/4096)) / (3/4)

=16.(4095/4096) / (3/4)

=16.(4095/4096). (4/3)

=16 (1365/1024)

=1365/64 = 22 57/64