Answer
$0.2091$
Work Step by Step
We need to take $\ln $ to each side of the equation:
$\ln 5^x =\ln 1.4$
Simplify it by applying rule $\log{a^n}=n \log x $ to obtain:
$ x \ln 5= \ln 1.4$
This implies that
$ x = \dfrac{\ln 1.4}{\ln 5} \approx 0.2091$
