What is the solution to this system of linear equations X+y=4
X-y=6
(4,6)
(6,4)
(5,-1)
(-1,5)

To answer this question, one must replace variables in both equations, and see if the answer matches.

For example: if we try (4,6)
X=4
Y=6
That means that 4+6=4? And
4-6=6?
No
You have to find the coordinates that satisfy both equations