I do not know what the student activities are, but I have an idea on what the problem might be.
I believe the push x, y direction is talking x, y coordinates of the actor and not the screen. The 0, 0 coordinate is in the top left corner of the screen, but in relation to itself, 0, 0 is the top left corner of the actor. Your hero would then be placed at 50, 300 (for example). That means hero x = 50 and hero y = 300. Pushing the enemy, towards 50, 300 in relation to itself would be pushing it almost straight downward. To push towards the hero, you would want the x direction to be "hero x - x of self" and y direction to be "hero y - y of self".
Given the hero is at 50, 300 example. Let's say the enemy is at 400, 300. Subtracting the enemy's coordinates would then give a direction of -350, 0. In relation to itself, that means straight left.