Question

Quantos termos possui a p.g se: a1=6
an=384
q=2

Answer 1

an = a1*q^n-1

384 = 6*2^n-1

384 / 6 = 2^n-1

64 = 2^n-1

iguala as bases

2^6 = 2^n-1

cancela as bases

6 = n - 1

6 + 1 = n

n = 7 termos