Question

qual a soma da PG,50, ... 500000

Answer 1

Resposta:

a1 = 5

a2 = 50

an = 500000

razão q = 50/5 = 10

an = a1.q^(n-1)

500000 = 5.10^(n-1)

500000/5 = 10^(n-1)

100000 = 10^(n-1)

10^5 = 10^(n-1)

(n-1) = 5

n = 5 + 1

n = 6

Sn = a1.(q^n  -1)/(q - 1)

S6 = 5.(10^6  -1)/(10-1)

S6 = 5.(1000000 - 1)/9

S6 = 5(999999)/9

S6 = 5.1111111

S6 = 555.555