
  You want to solve this nonlinear system of equations :

        a X**(1/2) + b Y**(1/2) + c Z**(1/2) = d
        e X**(1/2) + f Y**(1/2) + g Z**(1/2) = h
        i X**(1/2) + j Y**(1/2) + k Z**(1/2) = l

  If you write :

               X**(1/2) = x
               Y**(1/2) = y
               Z**(1/2) = z
    
  You can rewrite the system :

        a x + b y + c z = d
        e x + f y + g z = h
        i x + j y + k z = l

 Which is a linear system of equation in x, y, z.

 Suppose, the solution of the system is :

                    x = r
                    y = s
                    z = t 

 you can write
                 X**(1/2) = r    if r = 9/1  X = 81/1   
                 Y**(1/2) = s    if s = 2/5  Y =  4/25 
                 Z**(1/2) = t    ...
 
 The bad values for r, s, t are for example negative numbers.
