Statement 1 says that x+2y = 6 . This and the condition above tells me that x and 2y must be positive and equal to get a positive total 6. x-2y equals 0.
Statement 2 tells me that x and y can be negative together or positive together and that mod x is equal to mod 2y. Either way (positive or negative together), x-2y will equate to 0.
Regards
Anup
The only lines that matter - are the ones you make!