Respuesta :
[tex] \bf \textit{Logarithm Cancellation Rules}
\\\\
\stackrel{\stackrel{\textit{we'll use this one}}{\downarrow }}{log_a a^x = x}\qquad \qquad a^{log_a x}=x~\hfill\stackrel{recall}{ln=log_e}\qquad log_e(e^z)=z
\\\\[-0.35em]
\rule{34em}{0.25pt} [/tex]
[tex] \bf 0=-e^{-x}+3e^{3x}\implies e^{-x}=3e^{3x}\implies \cfrac{1}{e^x}=3e^{3x}\implies 1=e^x\cdot 3e^{3x}
\\\\\\
1=3e^xe^{3x}\implies \cfrac{1}{3}=e^{x+3x}\implies \cfrac{1}{3}=e^{4x}\implies ln\left( \cfrac{1}{3} \right)=ln\left( e^{4x} \right)
\\\\\\
ln\left( \cfrac{1}{3} \right)=4x\implies \cfrac{ln\left( \frac{1}{3} \right)}{4}=x [/tex]
and you plug that in your calculator to get about -0.27465307216702742285.
