Amarcord Federico Fellini and Mathcad (https://en.wikipedia.org/wiki/Amarcord):

I would like to use all Mathcad tools for the solution this problem:

 The author of the last solution will get the gift from me!

1.

We have used Find, root, MinErr, polyroots, Minimize and Maximize functions! 

We can use the lsolve function too! Why not! With Werner help!