Question

Como resolver $5^{x}$ = 0,5  e  $\frac{ 7,2 .10^{-6} }{ 1,8.10^{-5} }$ ?

Answer 1

$5^x=0.5$

$x= \log{0,5}_5$

Trocando as bases.

$x= \frac{\log~0,5}{\log~5}$

$\boxed{x=-0.43067655807}$

2° 

$\frac{7,2.10^{-6}}{1,8.10^{-5}} =4.10^{-1}$

$\lambda$