apabila U6 = 65 dan U10 = 97 dari deret aritmatika, tentukan a. beda b. suku ke 12

Mapel : matematika
Bab: Barisan dan deret

U6 = a + 5b = 65
U10 = a + 9b = 97
______________ _
-4b = -32
b = -32/-4
b = 8

a + 5b = 65
a + 5(8) = 65
a + 40 = 65
a = 65 - 40
a = 25

U12 = a + 11b
U12 = 25 + 11(8)
U12 = 25 + 88
U12 = 113

a)beda(b) = 8
b)U12= 113