Question

Selesaikan barisan geometri ini : Suku ke-4 = 27 dan suku ke-6 = 243, tentukan suku ke-8

Answer 1

U4 = 27 -> ar^3 = 27
u6 =243 -> ar^5 = 243

ar^5 = 243
r^2 (ar^3) = 243
r^2 × 27 = 243
r^2 = 243/27
r^2 = 9
r = 3

ar^3 = 27
a × 3^3 = 27
a = 27/27
a = 1

u8
= ar^7
= 1 × 3^7
= 2187