U1 + u10 + u 19 = 96 suku ke 10

U1 = a
U10 = (a+9b)
U19 = (a+18b)

U1 + u10 + u19 = 96
(a) + (a+9b) + (a+18b) = 96
(3a + 27b) = 96 >>> (dibagi 3)>>> (a + 9b) = 32

maka U10 = (a+9b) = 32

U1 = a
U10 = a + 9b
U19 = a + 18b

U1 + U10 + U19 = 96
a + a + 9b + a + 18b = 96
3a + 27b = 96 → Semuanya dibagi 3
a + 9b = 32

———

Jawaban → U10 = 32