Respuesta :

23dancer3
This last claim is because x can be thought of as 2+a, where "a" could be negative! Now x needs to go to 2-a, but solveing for "a" in x=2+a gives a=x-2, so the new x is 
2-a = 2-(x-2) = 4-x. 



(-1,1) => (5,1) 
(0,4) => (4,4) 
(-3,4) => (7,4)