tolong no 4 yaa.. pake cara yaa.. makasii:)

dik : U1 = a = 2
b = 5-2 = 3
n = 100
dit : U100........?
Un = a + (n-1).b
U100 = 2 + (100 - 1) .3
U100 = 2+900.3
U100 = 2702
semoga membantu.....☺