Question 197296
{{{5/(1+2e^(-x))=4}}} Start with the given equation 



{{{5=4(1+2e^(-x))}}} Multiply both sides by {{{1+2e^(-x)}}}



{{{5=4+8e^(-x)}}} Distribute



{{{5-4=8e^(-x)}}} Subtract 4 from both sides



{{{1=8e^(-x)}}} Combine like terms.



{{{1/8=e^(-x)}}} Divide both sides by 8



{{{1/8=1/e^x}}} Rewrite {{{e^(-x)}}} as {{{1/e^x}}}



{{{e^x=8}}} Cross multiply



{{{x=ln(8)}}} Take the natural log of both sides (to eliminate the base "e" and isolate "x")




So the solution is {{{x=ln(8)}}} which approximates to *[Tex \LARGE x \approx 2.07944]