>>7
Yea, basically they are two straight lines parallel to each other, but shifted by either - 7 or 19. It's common sense that they will never be equal.
One could use a second variable to further explain. Consider "y = x - 7" when drawn on the x-y coordinate plane. As you can see it is a straight line parallel to "y = x" but shifted down by 7 units. Now consider the line "y = x + 19" when drawn on the x-y coordinate plane. This one will be parallel to "y = x" and also parallel to "y = x - 7" but it will be shifted up (from "y = x") by 19 units. The lines never intersect, therefore x will never coincide in both statements making them true.