Question

Determine a soma dos 8 Primeiros termos da P.G. (3, 12, 48, ...)?

Answer 1

Formula : an = a1.q^n-1

an = ?

a1= 3

n= 8

q= 4

an= 3.4^8-1

an= 3.4^7

an= 3.16384

an= 49152

Sn= (an.q - a1)/q - 1

Sn= (49152.4 - 3)/4 - 1

Sn= 196605/3

Sn = 65535