A 5 ft ladder is placed against a wall. Suppose the bottom of the ladder is sliding away from the wall at a constant rate of 2 feet per second. How fast is the top of the ladder sliding down the wall when the bottom is 3 feet away from the wall?

Let x be the distance of the bottom of the ladder from the wall and let y be the distance of the top of the ladder from the ground.

What is x in the current problem?