Solution - Simplification or other simple results

Reformatting the input :

Changes made to your input should not affect the solution:

(1): "^-2" was replaced by "^(-2)".

Step  1  :

            4
 Simplify   —
            7

Equation at the end of step  1  :

  4
 (—)-2
  7

Step  2  :

 2.1     4 = 22

(4)^-2 = (2²)^(-2) = (2)^(-4)

Final result :

  1 • 72
  ——————
  1 • 24