Clear write up of the solution of this problem, but there's more you can add. Why did you do it this way? Did you consider any other approaches - or try them, even?
Consolidation: to finish, this post would benefit from a 'so what?' Why does this problem matter, or what did you get from doing it?
Once you get that the fractions give 25/28 of his life, what does that tell you about the extra +4+5?
Write something about yourself. No need to be fancy, just an overview.