## College Algebra 7th Edition

(a) $x=\dfrac{1}{e}$ (b) $x=-1$
RECALL: (1) $\ln{x}=y \longrightarrow e^y=x$ (2) $a^{-m}=\dfrac{1}{a^m}, a\ne0$ (a) Use rule (1) above to obtain: $\begin{array}{ccc} &e^{-1}&=&x \end{array}$ Use rule (2) above to obtain: $\dfrac{1}{e}=x$ (b) Use rule (1) above to obtain: $\begin{array}{ccc} &e^x&=&\dfrac{1}{e} \end{array}$ Use the rule (2) above to obtain: $e^x=e^{-1}$ Use the rule $a^m=a^n \longrightarrow m=n$ to obtain: $x=-1$