Solution - Simplification or other simple results

Reformatting the input :

Changes made to your input should not affect the solution:

 (1): "d2"   was replaced by   "d^2". 

(2): "0.084" was replaced by "(084/1000)".

Step  1  :

             21
 Simplify   ———
            250

Equation at the end of step  1  :

                21
  ((d2) • f) • ———
               250

Step  2  :

Final result :

  21d2f
  —————
   250