Susun rumus suku ke-n! A) 10,30,90,270,810,2430,..... B) 5,30,180,1080,6240,...... C) 1000,250,250/4,250/16,250/64,... D) 729,243,81,27,9,3,1,1/3,..... Tolong s

♻DERET GEOMETRI

a. 10, 30, 90, 270,...

a = 10
r = 30/10 = 3

Rumusnya
[tex]un = {ar}^{n - 1} \\ un = 10 \times (3)^{n - 1} [/tex]
b. 5, 30, 180,.....

a = 5
r = 30/5 = 6

Rumus suku ke n
[tex]un = 5 \times (6)^{(n - 1)} [/tex]
C. 1000, 250, 250/4,....

a = 1000
r = 250/1000 = 1/4

Rumus suku ke n
[tex]un = 1000 \times ( \frac{1}{4} )^{n - 1} [/tex]


Jawaban D, coba di cari dan di pelajari...


Semoga membantu, belajar pasi akan bisa.... ✔

1. a=10, r=3 ; Un=10.3^n-1=10/3 . 3^n
2. a=5 , r=6 ; Un=5.6^n-1=  5/6 . 6^n
3. a=1000, r=1/4 ; 1000. 1/4 ^n-1= 4000.1/4 ^n
4. a= 729, r=1/3 ; Un=729. 1/3 ^n-1= 2187. 1/3^n