Hello,

this is correct (*)

This is not correct (*),where do I go from here?

is this also correct ?

(*) if a and b are negative, there will be some problems for defining the logarithm...

Anyway, here is what I did :

- if a,b=0, then the equality is always true, for any x and y. So it is true to say that x+y=1

- if a,b=1, same as above

- if a,b 0 or 1 :

this is true iff , that is to say

similarly for b, we get

if x=0,

- if x+y-1=0, then y=1 and we have x+y=1

- if y=0, then there is a problem here...

if x+y-1=0, everything is ok.

I wonder if you stated all the conditions over a,b,x and y...