Question

Jika suku ke 7 barisan aritmatika adalah 22 dan suku ke 12 adalah 37 , maka suku ke 14 adalah

Answer 1

Verified answer

BARISAN ARITMATIKA

Un = a + (n - 1) b

U7 = 22
a + (7 - 1) b = 22
a + 6b = 22 ...(1)

U12 = 37
a + (12 - 1)b = 37
a + 11b = 37 ...(2)

• Eliminasi pers (1) dan (2)
a + 6b = 22
a + 11b = 37
_________ -
- 5b = - 15
b = 3

a + 6b = 22
a + 6(3) = 22
a = 4

U14 = ...?
U14 = a + 13b
U14 = 4 + 13(3)
U14 = 4 + 39 = 43

Answer 2

Verified answer

Diketahui:

U7 = a + 6b = 22

U12 = a + 11b = 37

Ditanyakan:

U14 = ... ?

Penyelesaian:

beda barisan

11b - 6b = 37 - 22

5b = 15

b = 3

suku pertama

a + 11b = 37

a + 11(3) = 37

a + 33 = 37

a = 4

U14 = a + 13b

U14 = 4 + 13 (3)

U14 = 4 + 39

U14 = 43

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Detil Jawaban

Kelas: 9

Mapel: Matematika

Bab: Barisan dan Deret Bilangan

Kode: 9.2.2

Kata Kunci: Barisan aritmatika