Answer
$x \approx -0.19$
Work Step by Step
RECALL:
$\ln{e^x} = x$
Take the natural logarithm of both sides to obtain:
$\ln{(e^x)}=\ln{0.83}$
Use the rule above to obtain:
$\ln{(e^x)}=\ln{0.83}
\\x = \ln{0.83}$
Use a scientific calculator to obtain:
$x =-0.1863295782
\\x\approx -0.19$