# optimization – How to minimize a function with two bad scaled unknown variables?

In my research, I have obtained an equation with two unknown variables. I have tried many optimization methods, both gradient-based and gradient-free ones, but unsuccessful. Maybe due to the fact that two variables are badly scaled. The equation f(x,y) is:
(1./364500000.)*exp(300.x)(405000.*exp(900.*x)*x^2-900.*exp(900.*x)*x+exp(900.x)-1)/(x^3y)-5.01693568940709373E-005=0
I know the solution is x=0.004 and y=400000. But what optimization method is able to find these two results? Is rescaling needed? Thanks in advance.
Kind regards