## Calculus 8th Edition

$x=ln3-ln7$
Given: $10(1+e^{-x})^{-1}=3$ Divide both sides by 10. $(1+e^{-x})^{-1}=\frac{3}{10}$ $\frac{1}{(1+e^{-x})}=\frac{10}{3}$ Hence, $x=ln3-ln7$