Page 192 - MTK 2024

KUNCI JAWABAN ASESMEN AKHIR MODUL

1. Penyelesaian
a. 2, 5, 8, 11, 14, ….
2 = 3(1) – 1

5 = 3(1) – 1

8 = 3(1) – 1

11 = 3(1) – 1

14 = 3(1) – 1

Jadi rumus suku ke-n = Un = 3n – 1

b. 9, 7, 5, 3, 1, ….

9 = -2(1) + 11

7 = -2(1) + 11

5 = -2(1) + 11

3 = -2(1) + 11

1 = -2(1) + 11

Jadi rumus suku ke-n = Un = -2(n) – 1

2. Jawab :

10
a. 1 + 2 + 3 + … + 10 =  i
i 1

15
b. 2 + 4 + 6 + … + 30 =  2i
i1

3. Jawab :

3
n
2
3 + 3 + 3 + … + 3

a = 3, r = 3, Sn = 363

n
n
a(r 1) 3(3 1)
n
S  (r 1)  363  (3 1) 363 x 2 = 3(3 – 1)
n

363x2
n
  (3  1)  242 + 1 = 3
n
3

= 243 = 3  n = 5
n

4. Jawab :

U2 = 8, berarti ar = 8

U3 = 64, berarti ar = 64
4
3
ar.r = 64
3
8r = 64