Respostas

2014-08-18T21:30:29-03:00
E aí Raphael,

use a propriedade da potência e a decorrente da definição:

logb^k~\to~k\cdot logb\\log_kk=1

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log_416=log_44^2\\
log_416=2\cdot log_44\\
log_416=2\cdot1\\\\
\boxed{\boxed{log_416=2}}\\.

________________

log_381=log_33^4\\
log_381=4\cdot log_33\\
log_381=4\cdot1\\\\
\boxed{\boxed{log_381=4}}\\.

________________

log_5125=log_55^3\\
log_5125=3\cdot log_55\\
log_5125=3\cdot1\\\\
\boxed{\boxed{log_5125=3}}\\.

________________

log100.000=log_{10}10^5~~.\\
log100.000=5\cdot log_{10}10\\
log100.000=5\cdot1\\\\
\boxed{\boxed{log100.000=5}}\\.

________________

log_864=log_88^2\\
log_864=2\cdot log_88~~~~~~~.\\
log_864=2\cdot1\\\\
\boxed{\boxed{log_864=2}}\\.

Ótimos estudos mano =))
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