Tolong jawab beserta caranya. Thanks.

U2 = ar^2-1
6 = ar

U5 = ar^5-1
48 = ar^4

cari rasio
ar^4/ar = 48/6
r^3 = 8
r = ∛8
r = 2

cari suku awal
U2 = ar
6 = ar
6 = a × 2
a = 6:2
a = 3

maka U3
U4 = ar^4-1
U4 = ar³
U4 = 3 × 2³
U4 = 3 × 8
U4 = 24