Solution - Simplification or other simple results

Step  1  :

Equation at the end of step  1  :

  20x -  5x2

Step  2  :

Step  3  :

Pulling out like terms :

 3.1     Pull out like factors :

   20x - 5x²  =   -5x • (x - 4) 

Final result :

  -5x • (x - 4)