how do i break down this polynomial x3+5X2-x-5

Question

how do i simplify this polynomial  X³  + 5X² -X - 5

Answer 1

By Grouping:

  You can observe that first 4 terms if you group by 2 have factor of X+5 common:

 

   X^3 + 5X^2 - X - 5 =

 

  X^2 ( X +5 ) - ( X +5) =

 

  ( X+5  ) (X^2 -1) =

 

  ( X+5 ) ( X+1) ( X -1 )