Suatu deret geometri tak hingga jumlahnya 58 dan suku pertama 4 tentukan rasionya..

Deret geometri tak hingga

Sn = 58
[tex] \frac{a}{1-r} = 58 \\ \frac{4}{1-r} = 58 \\ \frac{4}{58} = 1-r \\ \frac{2}{29} = 1-r \\ r = 1 - \frac{2}{29} \\ r = \frac{27}{29} [/tex]

RHNUR TRIK

58(1 - r) = 4
58 - 58r = 4
58r = 58-4
58r = 54
r = 54/58 = 27/29