Question

Kak tolong dong no 7 ,gak nemu" caranya ..

Answer 1

(i) U9 = 768 (BENAR)

periksa =
a = 3
U2 = 6
merupakan barisan geometri
r = 6 ÷ 3 = 2
U9 = ar^(n-1)
U9 = 3 x 2^8
U9 = 3 x 256 = 768

(ii) U10 = 1526 (salah)

U9 = 768
U10 = 768 x 2 = 1536

(iii) S6 = 179 (salah)

rumus = a(r^n-1)/r-1 = 3(2^6 -1)/2-1 = 63 x 3 =189

(iv)S7 = 381 (benar)
rumusa = a(r^n -1)/r-1 = 3(2^7 -1)/2-1 = 3(127) = 381

jadi jawabannya
(i) dan (iv) = B