Solve for x: (700)/(1+e^-x)=675

ok this is what i did i solve it all the way to where i got the natural log like so Ln(e^-x)=Ln(1/27) then i get -Ln(1/27) i plug that into my calculator and got 3.296. but when i plugged 3.296 back into the equation i did not get 675. so im am super stuck. please help.