Question 1119660
.
<pre>
a)  Regarding the equation     //   !!  <U>as it is written in your post</U>  !!

    x^5+ x^4+ x^3+ x^2+1=0,


    your factoring is INCORRECT, since it implies that x= -1 is the root,

    while easy inspection shows it is not.


    The same arguments disprove the solution by the other tutor.



b)  {{{2x^2y^2+2y^2z^2+2x^2z^2-x^4-y^4-z^4}}}
~~~~~~~~~~~~~~~~~~~~~~


    Regarding this factoring, see this video-lecture 


    https://www.youtube.com/watch?v=SWMPwVlF07g
</pre>