y < -x + 3
to check if a point is a solution, you have to replace the point into the inequality and verify the final result.
Replacing with (0,3) we get:
3 < -0 + 3
3 < 3
which is not true, then (0,3) is not a solution
Replacing with (0,0) we get:
0 < -0 + 3
0 < 3
which is true, then (0,0) is a solution
Replacing with (-2,-2) we get:
-2 < -(-2) + 3
-2 < 2 + 3
-2 < 5
which is true, then (-2,-2) is a solution
Replacing with (1,4) we get:
4 < -1 + 3
4 < 2
which is not true, then (1,4) is not a solution
Replacing with (-7,4) we get:
4 < -(-7) + 3
4 < 7 + 3
4 < 10
which is true, then (-7,4) is a solution