Question 744924
The problem states:

Express y as a function of x. What is the domain?
a) log(base 2)xy = 3log(base 2)x
b) log(base 5)y = 2log(base 5)x+1 + log(base 5)x-1
b) log(base 3)y-3 = 1 + 2log(base 3) 

First notice that each problem has the same log base on both sides of =

a) we can divide both sides of = by log(base 2) which gives us
   xy = 3x and y = 3  (all rational numbers)

b) divide both sides of = by log(base 5) and we get
   y = 2x+2 + x-1
   y = x+1 (domain is all rational numbers)

c) divide both sides of = by log(base 3) and we get
   y-3 = 1 + 2
   y = 6  (domain is all rational numbers)