Tentukan jumlah 10 suku pertama dari A.9,19,29 B.-30,-26-24

A)
a = 9
b = 19-9 = 10
U10 = 9 + 9×10 = 99
S10 = 10/2 x (9+99) = 5 x 108 = 5.040

b)
-30-26-24
a = -30
b = -26+30 = 4
U10 = -30 + 4 x 9 = 6
S10 = 10/2 x ( -30+6) = 5 x (-24) = -120