Solution - Simplification or other simple results

Step  1  :

Equation at the end of step  1  :

  ((0 -  (3•5a2)) +  16a) -  a

Step  2  :

Step  3  :

Pulling out like terms :

 3.1     Pull out like factors :

   15a - 15a²  =   -15a • (a - 1) 

Final result :

  -15a • (a - 1)