Question

Dik : Suatu barisan geometri suku ke-2 = 12 dan suku ke-5 = 324.
Dit: U4?..

Answer 1

U2 = ar = 12
u5 = ar^4 = 324

r^3 = ar^4/ar = 324/12 =27
r =∛27 = 3

a r = 12
a x 3 = 12
a= 4

u4 = ar^3
     = 4 x 27
     = 108