tolong yaa dibantu nomor 9 , thankss

Pola : 3,9,18,...
6,9, ,...
3, 3,....

a = 3
b = 6
c = 3

U10 = a+(n-1)b + c (n-1)(n-2)/2
= 3+9.6 + 3.9.8/2
= 3+54+108
= 165