Question

Quantos termos tem a pg (1/9,1/3,...,27)

Answer 1

a1=1/9
q=1/3:1/9=1/3.9/1=9/3=3

an=27
an=a1.q^(n-1)
27=1/9.3^(n-1)
27:1/9=3^(n-1)
27.9/1=3^(n-1)
243=3^(n-1)
3^5=3^(n-1)
5=n-1
n=5+1
n=6

Essa PG tem 6 termos