Question 979387
Add up the equations to get


3x-y=-6
3x+y=6
-------
6x+0y = 0


That leads to 6x = 0 which means x = 0. You then use x = 0 to find y. Plug it into any equation with x & y in it. You'll find that y = 6.


So there is exactly one solution and it is the ordered pair (0,6)