diketahui barisan geometri dengan U3 = 24 dan U6 = -192. Tentukan a.rasio b.suku pertama c.suku ke-10.

a.
U6= a × r^6-1 = a × r^5 = -192
U3 = a × r^3-1 = a × r² = 24
_______________________÷
. . . . . . . . . . . . . . r^3 = -8
. . . . . . . . . . . . . . r = -2

b.
U1 × r² = 24
U1 × (-2)² = 24
U1 × 4 = 24
4U1 = 24
U1 = 6

c.
U10 = a × r^n-1
= 6 × (-2)^10-1
= 6 × (-2)^9
= 6 × (-512)
= -3.072