First of all to express as take the exponential of both sides and then subtract 2 from both sides:
Then for the values for which x and y are defined you have to look at which values are not possible in the original equation:
Dealing with values of x and first looking at the square root sign it must be true that otherwise we would be taking the square root of a negative number which isn't allowed. Going on to look at we must use values or else we would be taking the ln of a number which does not exist.
So the values of x for which the equation is defined would be:
where x is a member of
Looking at values for y there is only one restriction shown by in the same way to the earlier log it must be so:
where y is a member of
If you have further questions just ask.