we have the expression
[tex]x^3-125[/tex]we have that
x=5 is a zero of the given equation
so
Divide x^3-125 by (x-5)
x^3-125 : (x-5)
x^2+5x+25
-x^3+5x^2
---------------
5x^2-125
-5x^2+25x
------------------
25x-125
-25x+125
----------------
0
therefore
x^3-125=(x-5)(x^2+5x+25)
