Respuesta :
It will depend on the sign of 2y. If it's positive;
3x-4y=7
3x+2y=-5
___________
-6y=12
If 2y is, however, negative;
3x-4y=7
3x-2y=-5
------------
-2y=12
3x-4y=7
3x+2y=-5
___________
-6y=12
If 2y is, however, negative;
3x-4y=7
3x-2y=-5
------------
-2y=12