Question 1006433
{{{75=100-100e^(-0.01x)}}}
{{{100e^(-0.01x)=100-75}}}
{{{100e^(-0.01x)=25}}}
{{{e^(-0.01x)=25/100}}}
{{{e^(-0.01x)=0.25}}}
{{{-0.01x=ln(0.25)}}}
{{{0.01x=-ln(0.25)}}}
{{{x=-ln(0.25)/0.01}}}<-->{{{x=-ln(1/4)/0.01}}}<-->{{{x=ln(4)/0.01}}}<-->{{{x=100ln(4)}}}
So {{{highlight(x=100ln(4))}}} is an elegant way to write the exact result,
but {{{x=-ln(0.25)/0.01}}} would allow you to calculate an approximate result with a calculator.