Suatu Barisan artimatika suku pertamanya 5 dan suku ke 5 adalah 22. tentukan,

U1 atau a = 5

U5 = 22

dit:

b = ?

U95 = ?

Un = ?

jwb:

U1 = 5

U5 = 22

U1 = 5

a + (n – 1)b = 5

a = 5

U5 = 22

a + (n – 1)b = 22

5 + (5 – 1)b = 22

5 + 4b = 22

4b = 17

b = 17/4

U95

= a + (n – 1)b

= 5 + (95 – 1)(17/4)

= 5 + 94 . 17/4

= 5 + 399,5

= 404,5

Un

= a + (n -1)b

= 5 + (n – 1)(17/4)

= 5 + 17/4n – 17/4

= 17/4n + 3/4