Page 6 - BARISAN DAN DERET ARITMATIKA_DIVA AUBERTA NARISWARI_2102110002

R U M U S D E R E T

A R I T M A T I K A

K E T E R A N G A N :

S N = J U M L A H S U K U K E - N

U N = S U K U K E - N

A = S U K U P E R T A M A

C O N T O H S O A L

1 . T E R D A P A T S E B U A H B A R I S A N B I L A N G A N S E P E R T I B E R I K U T 3 , 5 , 7 , 9 , . . .

B E R A P A K A H S U K U K E - 3 0 D A R I B A R I S A N T E R S E B U T ?

P E M B A H A S A N :

D I K E T A H U I :

- U 1 = 3
- U 2 = 5

- U 3 = 7

- U 4 = 9

- B = 2

- A = 3

- N = 3 0

D I T A N Y A :

U 3 0 ?

J A W A B :

U 3 0 = A + ( N - 1 ) B

= 3 + ( 3 0 - 1 ) 2
= 3 + 2 9 . 2

= 3 + 5 8

= 6 1

2 . T E R D A P A T S E B U A H D E R E T A R I T M A T I K A S E B A G A I B E R I K U T 2 0 + 1 8 + 1 6 + . . .
T E N T U K A N B E R A P A J U M L A H 1 5 S U K U P E R T A M A N Y A !

P E M B A H A S A N :

D I K E T A H U I :

- U 1 = 2 0

- U 2 = 1 8

- U 3 = 1 6

- B = - 2
- A = 2 0

- N = 1 5
D I T A N Y A :

S 1 5 ?

J A W A B :

3