SOLUTION: if x/y=4y/x=z, then find all possible values of z.

The first equation is


     = ,


and it implies


    x^2 = 4y^2,

or

    x = +/-  = +/- 2y.


Then  EITHER  z =  = 2   OR   z =  = -2.


These two values for z are two possible solutions/answers to the problem.