Question

Quantos termos tem a PG (3,9,....,729)?

Answer 1

a1=3
a2=9
razão=9/3=3
an=729

an=a1.q^n-1
729=3.3^n-1
243=3^n-1
3^5=3^n-1
3^n-1=3^5
n-1=5
n=5+1
n=6