tolong bantu jawab no. 10 ya... pakai cara nya... makasih :)

jawabannya 13.122 yayayyaa

U4-2= 2
54 :2 = 27
54 : 6 = 9
27 - 9 = 18
r = 18 : 6 = 3
U1= a = 6 : 3= 2
Un = ar^n-1
U8 = 2x 3^8-1
= 2x 3^7
= 2x 2187
= 4374.....C