Suku ke-8 dari barisan geometri :-192,96,-48,24 ...adalah...

Bab Barisan dan Deret
Matematika SMP Kelas IX

geometri
r = 96/-192 = -1/2

U8 = a x r^7
U8 = -192 x (-1/2)^7
U8 = 192/128
U8 = 3/2

geometri : -192, 96, -48, 24

U1 = a = -192
rasio = r = U2/U1
= 96/(-192) = -½

U8 = a × (r)^n-1
= -192 × (-½)^8-1
= -192 × (-½)^7
= -192 × (-1/128)
= 192/128 = 3/2

^ = pangkat