Jika suku ke-6 dari barisan aritmatika sama dg 27dan suku ke-12 adalah 48 Carilah suku ke 10

U6 :
a + 5b = 27
a = 27 - 5b

U12 :
a + 11b = 48
(27 - 5b) + 11b = 48
6b = 48 - 27
6b = 21
b = 21/6
b = 7/2

a = 27 - 5b
a = 27 - 5(7/2)
a = 27 - 35/2
a = 54/2 - 35/2
a = 19/2

U10 = a + 9b
U10 = 19/2 + 9(7/2)
U10 = 19/2 + 63/2
U10 = 82/2
U10 = 41

semoga membantu ^_^