Suatu barisan geometri 15,45,135,..... Tentuka besar suku ke 10

jawab
bar geometrri

15, 45, 135,...
a = 15
r = 45 : 15 = 3

u10 = a . r^9 = (15). (3)^9 = 295.245

suku ke 3 = 135
4 = 405
5 = 1215
6 = 3645
7 = 10935
8 = 32805
9 = 98415
10 = 295.245
jadi, suku ke-10 = 295.245