Possibility of determining a certain length in a triangle. The figure is on the bottom of the question.
Suppose I have a triangle $ABC$ with an additional point $M$ on the middle of $AB$. Suppose that I know the following three quantitites, where $\ell(\cdot)$ represents the lenth of the line.


*

*$y:=\ell(AM)$

*$k:=\ell(AC) - \ell(CM)$ 

*$l:=\ell(BC) - \ell(CM)$


Is it possible to determine $x:=\ell(CM)$? And if so, is this value unique?
Thank you in advance.
EDIT:


The 2nd and 3rd values determine two hyperbolas (with foci respectively $M,A$ and $M,B$).
The point C is the intersection of these two hyperbolas.
So yes, it's possible.   
We first draw $A,B,M$, this we can obviously do. Then we draw the two hyperbolas, we see where they intersect, and that determines $C$ (I do not say it's a unique $C$, maybe there are more than $1$ or maybe $0$ solutions for $C$, I didn't investigate that).    
See also:  Hyperbola 
