Question

2/5 elevado ×-1=125÷8

Answer 1

$(\frac{2}{5})^{x-1} = \frac{125}{8}\\\\ Log_{\frac{125}{8}}\frac{2}{5}=x-1\\\\ x = Log_{\frac{125}{8}}\frac{2}{5} +1\\\\ x = \frac{Log\frac{2}{5}}{Log\frac{125}{8}} +1\\\\ x = \frac{-0,916290732}{2,748872195}+1\\\\ \boxed{x \approx 1,333333}$

Bons estudos!