SOLUTION: If x^y = a and x^4y-4 = 77, find the value of a

I read your post (your formulas) in this way:



        If   = a  and   = 77,  find the value of  a.



Then    = ,  and the given equation is


     = 77  ====>   = 77 + 4 = 81.


It implies that "a" may have four possible values:


    - two real values  a= 3  and  a= -3,


    - and two imaginary values  a= 3i  and  a= - 3i.

 ------ Substituting 

, and so,