Pada barisan arimatika diketahui u9 =35 dan u12=47,maka nilai u5 ​

Penjelasan dengan langkah-langkah:

U9 = a+ (9-1) b

35 = a + 9b -b

35 = a + 8b

U12 = a + (12-1) b

47 = a + 12b – b

47 = a + 11b

a + 11b = 47

a + 8b = 35

_________ –

3b = 12

b = 4

U9 : 35 = a + 8b

35 = a + 8.4

35 = a + 32

35 – 32= a

3 = a

U5 = a + (n-1) b

U5 = 2 + (5-1) 4

= 2 + 16

U5 = 18