Thank you! BTW, can you tell me, from which software is this screenshot? I found same answer (Lambert W formula) hidden somwhere in plot graph on Wolfram Alpha, but with no steps shown. I'curious how to go from one formula to second one.

I used Mathcad to generate the result. The two approaches are not related. For the first, search for LambertW, for the second, search for Newton-Raphson (Wikipedia will give details for both).