Question

Diketahui barisan geometri mempunyai suku ke 3 bernilai 6 dan suku ke 6 bernilai -48 . Nilai suku ke 9 barisan terdengar adalah...

Answer 1

Verified answer

U6/U3 = -48/6
ar^5/ar² = -8
r³ = -8
r³ = (-2)³
r = -2

U3 = 6
ar² = 6
a= 6/r² = 6/(-2)² = 6/4 = 3/2

U9 = ar^8 = (3/2) (-2)^8 = (3/2)(256) = 384