Question

A soma log 2/3 + log 3/4 + log 4/5 + ................. + log 19/20 é igual a:

a) -log 20
b) -1
c) log 2
d) 1
e) 2

Answer 1

Ola 

log(2/3) + log(3/4) + log(4/5) + ... + log(19/20) 

log(2) - log(3) + log(3) - log(4) + log(4) - log(5) + ... + log(19) - log(20) 

log(2) - log(20) = log(2) - log(2) - log(10) = -log(10) = -1 (B)