Tank push back

I try to push my enemy tank back if it got hit . But the problem is the direction

The tank move from right to left and the left and right.

if it moves from right to left i use tank.X =tank.X -20 to push it back.

for left would than be tank.X=tank.X+20

How can a find out in with direction the tank is headed...?

I hope someone can help. I used the bullet movement for the Movement.

Thank you..

Martin...

You can read the angle of the Tank which will show you the direction and then simply add 180 to invert it.