Question

Determine a soma dos oito primeiros termos de cada P.G A)  (5000,500,50...)

Answer 1

Q = a₂/a₁
Q = 500/5000
Q = 1/10

$S_{n} = \frac{a_{1} . (q^n -1) }{q -1}$
s8 = 5000 . [(1/10)^8 -1]/(1/10 -1)
s8 = 5000 . [1/100000000 -1] . 10/9
s8 = 5000 . 99999999/100000000 . 10/9
s8 = 5000 . 999999990/900000000
s8 = 5555.5555