Question

Sabendo que log 2= 0,30 e log 3=0,48,calcule o valor de log 0,72.

Answer 1

Veja que:

$0,72=\frac{2^3*3^2}{10^2}\\ \\ log0,72=log(\frac{2^3*3^2}{10^2})\\ \\ log0,72=log2^3+log3^2-log10^2=3log2+2log3+2log10=\\ \\ =3*0,30+2*0,48+2*1=-0,14$