I'm thinking that it might be helpful if you put brackets around certain parts in order to make the equation not ambiguous. Eg if a = 81, and b = y/27, and c = x, then you're looking at a^(b^c) = 9 ?

And if a = 7, b = x+1, c = 49, d = y, then are you looking at (a^b)/(c^d)? Or a^{(b/c)^d} etc ?

And also same with the other equation..... if a = 6, and b = 36*(2x-1), and c = x, then you're looking at a^(b^c) = 1 ?