Put it in reverse and ease off of the breaks
57.4% = 0.574 in decimal form. Hope I helped!
Start by reviewing your knowledge of natural logarithms. If we take the ln of both sides we get e^z=ln(1). Do the same thing again and wheel about the ln(ln(1)). There's going to be complex solutions, Wolfram Alpah gets them but let me know if you figure out how to do it?