The equation has only a single variable, F. In physics, capital F is usually force, as in F=ma (force equals mass times acceleration). Since his equation has only a single unknown it is easily solved:
(2.27 - F)2.09 = 62.8
If I were home I'd use MathCad to give you an exact answer, but just by inspection it appears that F has two roots of approximately 9 and -5.
The author of the webpage is correct in describing the equation as simple, but it has nothing to do with the solar system, and the claims on the webpage are complete nonsense. If you go here:
You'll see that he actually "stole" what he posted from someone else, since this link includes additional data.
--Percy