Solution - Simplification or other simple results

Step  1  :

 1.1     4 = 22

(4)¹ = (2²)¹ = 2²

Equation at the end of step  1  :

  ((21) +  (31)) +  22

Step  2  :

Equation at the end of step  2  :

  ((21) +  3) +  22

Step  3  :

Equation at the end of step  3  :

  (2 +  3) +  22

Step  4  :

Final result :

  9