Question

calcule a soma dos 7 primeiros termos da P.G( 8;4;2;1;1/2;...)

Answer 1

a1 = 8
q = a2/a1
q = 4/8
q = 1/2
n = 7
Sn = a1.(1-q^n)/(1-q)
Sn = 8 . [1-(1/2)^7]/(1-1/2)
Sn = 8 . [1-1/128]/1/2
Sn = 2.8.[128/128 - 1/128]
Sn = 16 . 127/128
Sn = 2032/128
Sn = 508/32
Sn = 127/8

Answer 2

R = 1/2

8+4+2+1+1/2+1/4+1/8+1/10

Faça ae agr mano uahuaha