Solution - Simplification or other simple results

Step  1  :

            4
 Simplify   —
            7

Equation at the end of step  1  :

        5   4
  0 -  (— • —)
        6   7

Step  2  :

            5
 Simplify   —
            6

Equation at the end of step  2  :

        5   4
  0 -  (— • —)
        6   7

Step  3  :

Final result :

  -10            
  ——— = -0.47619 
  21