Question

Usando apenas que log 20 = 1, 30 log 30 = 1, 47 e log 60 = 1, 79 calcule: log 5 + log 12

Answer 1

$log(5)+log(12)=log(5\times12)=log(60)=log(20\times3)=log(20)+log3$ $=1.3+log3$

$1.47=log(30)=log(3\times10)=log3+log(10)=log3+1$
$1.47=log3+1$
$log3=0.47$

$1.3+log3=1.3+0.47=\boxed{\boxed{1.77}}$

Answer 2

Resposta:

a)    log4 + log 5 = log 4.5 = log 20 = 1,30

b) log 150 - log 5 = log 150:5 = log 30 = 1,47

c) log 16 + 2.log5 = log16 + log 5² = log 16. 25 = log 400 = log 20² = 2log20= 2. 1,30 = 2,60

d) 2log15 - log 4= 2. 1,1761 - 0,6021 = 2,3522 - 0,6021 = 1,7501

Explicação passo-a-passo: