Verified answer

Sabendo que:

log (a.b) = log a + log b e que

log(a/b) = log a - log b, temos:

.

log 15 = log (30/2) = log (3.10/2) = log 3 + log 10 - log 2

= 0,48 + 1 - 0,30 = 1,18

log5 = log(10/2) = log10 - log2 = 1 - 0,30 = 0,70

log15 = log(5.3) = log5 + log3 = 0,70 + 0,48 = 1,18

log 15 = log 3*5= log 3*10/2 = log 3 + log 10 - log 2

log 15 = 0,48 + 1 - 0,30 = 1,18

=======================

log(15) = log(30/2) = log(10) + log(3) - log(2) = 1 + 0,48 - 0,30 = 1,18

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