Chapter 5 - Exponential and Logarithmic Functions - 5.4 Logarithmic Functions - 5.4 Assess Your Understanding - Page 296: 104

$x=\frac{1-ln{13}}{2}$

If $e^{-2x+1}=13$, then by taking the natural logarithm of both sides we get $-2x+1=ln{13}$. Solve the equation above to obtain: \begin{align*}-2x=ln{13}-1\end{align*} \begin{align*}x=\frac{1-ln{13}}{2}\end{align*}