Solution - Simplification or other simple results

Reformatting the input :

Changes made to your input should not affect the solution:

(1): "10.5" was replaced by "(105/10)".

Step  1  :

            21
 Simplify   ——
            2 

Equation at the end of step  1  :

  21
  —— • 4
  2 

Step  2  :

Final result :

  42