Question

Tentukan suku ke-10 dari setiap barisan bilangan berikut.
a. 2, 5, 8, 11, ...
b. 16, 32, 64, 128, ....
c. 35, 31, 27, 23, ....
d. 108, 36, 12, 4, ....

Tolong bantuannya lengkap dengan caranya, saya kasih 12 poin. Thanks

Answer 1

A. U10= a+(n-1).b
2+(10-1).3
2+9.3
2+27= 29

Answer 2

A.)
a= 2
b= U2-U1= 5-2= 3
U10
= a+(n-1)b
= 2 + (10-1)3
= 2 + 9×3
= 2 + 27
= 29

b.)
a= 16
r= 32:16= 2
U10= ar^n-1
= 16×2^9
= 16×512
= 8.192

C.)
a=35
b= 31-35= -4
U10= a+(n-1)b
= 35 + 9×(-4)
= 35 + (-36)
= -1

d.)
a= 108
r= 36:108= 1/3
U10= ar^n-1
= 108×1/3^9
= 108× 1/19.683
= 1/182.25