Question

Suku ke 6 dan ke12 suatu barisan aritmatika berturut turut 35 dan 65 suku ke 52 barisan tersebut adalah,?

Answer 1

U6 = 35
u12 = 65
u52=...?
u6 = a + 5b
35 = a + 5b
a = 35 - 5b

u12 = 65
a + 11b = 65
a = 65 - 11b

35 - 5b = 65 - 11b
35 - 65 = -11b + 5b
-30 = - 6a
a = 5
u6 = a+ 5b
35 = 5 + 5b
30 = 5b
b = 6
u52 = a + 51 b
     = 5 + 51 (6)
       = 5 + 306 = 311