Question

Calcule a soma dos 10 primeiros termos da PG (5,10,20...)

Answer 1

$PG (5,10,20...)\\\\ S_n=?\\ a_1=5\\ n=10\\ q=2\\\\\\ S_n= \frac{a_1*(q^n-1)}{q-1} \\\\\\ S_n= \frac{5*(2^{10}-1)}{2-1} \to \\\\ S_n= \frac{5*(1024-1)}{1} \to \\\\ S_n= \frac{5*1023}{1} \to\\\\ S_n= 5115$