Solution - Simplification or other simple results

Reformatting the input :

Changes made to your input should not affect the solution:

 (1): "a1"   was replaced by   "a^1". 

Step  1  :

Equation at the end of step  1  :

  0 -  ((23•3a16) • a)
 Step  2  :

Final result :

  ( -23•3a17)