y = - x + 3
OK, KJ...let's see
When x = Then y = Point
-1 -(-1) + 3 = 4 (-1, 4) so the first answer isn't correct
1 -1 + 3 = 2 (1, 2)
0 - 0 + 3 = 3 (0, 3) so the second answer isn't correct
0 0 + 3 = 3 (0, 3)
4 -4 + 3 = - 1 (4, -1) Looks like the 3rd answer is correct
Do you see how to do this???