calcule a soma dos 13 primeiros termos da P.G(02,06,18...)
6/2= 3 logo q=3
entao façamos:
[tex]S_n=\frac{a_1(q^n-1)}{q-1}\\S_1_3=\frac{2(3^1^3-1)}{3-1}\\S_1_3=\frac{2(1594323-1)}{2}\\S_1_3=\frac{2*1594322}{2}\\S_1_3=\frac{3188644}{2}\\\\S_1_3=1594322[/tex]
Lucida,
Numa PG:
Sn = a1(q^n - 1) / (q - 1)
Do enunciado:
q = 18/6 = 6/2 = 3
a1 = 02
n = 13
S13 = 02(3^13 - 1) / (3 - 1)
= 02(1594323 - 1) / (2)
= 02(1594322) / 2
= 1594322
S13 = 1594322
