Help with simplify in CAS

[rawi]

dsfantos wrote:

Quote:with simplify it doesn't work

You are absolutely right: Simplify does not change anything.

If you apply epand to the expression you get:
4.2W^3 - 20.8*w^2+4.1*w+4.1+20.5*w-4.1 which is quite near to what you wanted.
Applying simplify to the result again does not change anything. Indeed this is very easy to simplify. A 5th grade pupil should see that +4.1 and -4.1 could be combined. A CAS-system should be able to do it.

Applying collect delivers a somewhat other result I am not sure whether this is correct:
4.2*w*(w-3.)*(w-1.952381)