Chapter 12 - Exponential Functions and Logarithmic Functions - 12.6 Solving Exponential Equations and Logarithmic Equations - 12.6 Exercise Set - Page 825: 20

$x\approx2.996$

Taking the natural logarithm of both sides and using the properties of logarithms, the value of the variable that satisfies the given equation, $ e^t=20 ,$ is \begin{array}{l}\require{cancel} \ln e^t=\ln20 \\\\ t\ln e=\ln20 \\\\ t(1)=\ln20 \\\\ t=\ln20 \\\\ x\approx2.996 .\end{array}