If xy > 0, does (x-1)(y-1)=1? which of x+y=xy, x=y will...?

[pck2103]

If xy > 0, does (x-1)(y-1)=1
a.) x+y=xy
b.) x=y

Which one of these equations will tell you if its true.

I dont understand why you even need the equations, when you factor it, can you say that
x =1 and y =1, so why do I need the equations below? Arent the only solutions, for this 1?

Am I looking at this the wrong way?

Thanks for the help.

 

[Denis]

Re: Equation Question, HELP!

1 + 1 = 2 ; 1 * 1 = 1
2 + 2 = 4 ; 2 * 2 = 4
3 + 3 = 6 ; 3 * 3 = 9
.....
kapish?