After resting they decided to go for a swim. The depth of the water is w times Dean's height. Dean is x feet taller than Ron. If Ron stands at y feet How deep was the water?
Ron's height is h.

Dean's height is h+x.

The depth of the water is w*(h+x).

Now you have all the information you need. You know that h=y-x. Substitute it and simplify the equation.