Sorry in advance, is my first question and i found something weird in wolfram
The problem:
Given a function f, and a chain of links with lengths (h0, h1, h2...), calculate the points where every chain links end following the f function, starting in (0,0).
In this case
. Take only the range [0, a)
Graphically this question is trivial:
an so on... Every crossing point is the center of the next circle with radius hn.
The question here is: solve it using algebra/calculus.
The result equation is easy too: 
where w is x of the previous iteration (in first iteration is 0)
Now, I want to take and clear x, and wolfram comes and says to me
Are that symbols maths beyond my knowledge (is possible) or I broke wolfram alpha?
Exists an easiest solution to this problem I'm not seeing?
No, you did not break WolframAlpha. You asked it to solve a problem that led to a $6$th degree polynomial equation and it tried to find its roots. But it found no closed formula for them. That's its way of talking about those roots. You will find more about it here.