asking name

[sujoy]

I just want to ask you is there any site which lists some techniques of solving things as
x+y=xy =>x+y-xy-1=0 I had taken a long time in solving this
I s there a site which gives cunning techniques as this

 

[Gene]

You are confusing me again. Is this algebra or symbolic logic or something else. I ask 'cause it doesn't make sense to me as either of those.
Algebra:
Substituting
x+y-xy =
x+y-(x+y)-1 =
x-x+y-y-1 =
-1=0
Inconsistant. No answer.

Logic:

x+y=xy
x y xy x+y
0 0 0   0
0 1 0   1
1 0 0   1
1 1 1   1

Not = so the given is false?