mohon bantuannya ya..pakai cara nya ya.nomor 1 doang

Kelas 8 Matematika
Bab Barisan dan Deret Bilangan

a] r = ⁶⁻⁴√(U6 : U4)
r = ²√(10/81 : 10/9)
r = √(10/81 : 9/10)
r = √(1/9)
r = 1/3

a = U4 : r³
a = 10/9 : (1/3)³
a = 10/9 : 1/27
a = 10/9 . 27
a = 30

b] U10 = U6 . r⁴
U10 = 10/81 . (1/3)⁴
U10 = 10/81 . 1/81
U0 = 10/6.561