Suku ke 6 dari barisan bilangan 64,-32,16,-8

r = u4/u3
= -8/16
= -1/2

Un = a.r^(n-1)
U6 = 64 × (-1/2)^5
= 64 × (-1/32)
= -64/32
= -2

Bab Barisan dan Deret
Matematika SMP Kelas IX

Geometri
r = U2 / U1
r = -32/64
r = -1/2

U6 = U2 x r⁴
U6 = -32 x (-1/2)⁴
U6 = -32 x 1/16
U6 = -2