Respostas

2014-04-23T22:08:36-03:00
4=2^2 e 8 = 2^3

(2^2)^x =2^3

2^2x = 2^3

Logo
2x=3

X=3/2
2014-04-23T22:10:31-03:00
Transforme o 4 e o 8 para base 2.

4^x=8\\\\(2^2)^x=2^3\\\\2^{2x}=2^3~~~~\Rightarrow~~2x=3~~~~\Rightarrow~~\boxed{x= \frac{3}{2} }