4=4.74+log(x/(0.0125-x)),
-0.74=log(x/(0.0125-x)).
If we assume logs to base 10:
0.18197=x/(0.0125-x),
0.18197(0.0125-x)=x,
0.0022746-0.18197x=x,
1.18197x=0.0022746, x=0.0022746/1.18197=0.0019244 approx.
If we assume natural logs:
-0.74=ln(x/(0.0125-x)),
0.47711=x/(0.0125-x),
0.0059639-0.47711x=x, x=0.0059639/1.47711=0.00403755 approx.