a) Regarding the equation // !! as it is written in your post !! 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)~~~~~~~~~~~~~~~~~~~~~~ Regarding this factoring, see this video-lecture https://www.youtube.com/watch?v=SWMPwVlF07g