Question

calcule a soma dos termos da pg (1,3,...,243).

Answer 1

Boa tarde

PG

u1 = 1
u2 = 3

q = u2/u1 = 3

termo geral
un = u1*q^(n - 1)
1*3^(n - 1) = 243
3^(n - 1) = 3^5
n = 6 termos

soma
Sn = u1*(q^n - 1)/(q - 1)
Sn = 1*(3^6 - 1)/(3 - 1)
Sn = 364