Answer
a.) $x = e^3$
b.) $x = 2$
Work Step by Step
$Use$ $the$ $definition$ $of$ $the$ $logarithmic$ $function$ $to$ $find$ $x:$
a.) $\ln x = 3$
b.) $\ln e^2 = x$
a.) $\ln x = 3$
Rewrite the natural log form to exponential form: $\ln a = b \rightarrow e^b = a$ [Note: e stands for euler's number, NOT a variable]
$\ln x = 3 \rightarrow e^3 = x$
$x = e^3$
b.) $\ln e^2 = x$
Bring the square to the front of the logarithm
$2\ln e = x$
$2\times1 = x$ [Note: $\ln e = 1$]
$x = 2$