Odpowiedź:
[tex]a)\ \ n^2(n-1)(n^2+1)=(n^3-n^2)(n^2+1)=n^5+n^3-n^4-n^2\\\\b)\ \ n^2(n+1)(n^2-1)=(n^3+n^2)(n^2-1)=n^5-n^3+n^4-n^2=n^5+n^4-n^3-n^2\\\\c)\ \ (x+2)(x^2-3x+1)=x^3-3x^2+x+2x^2-6x+2=x^3-x^2-5x+2\\\\d)\ \ (x^2+x+1)(x^2-x+1)=x^4-x^3+x^2+x^3-x^2+x+x^2-x+1=\\\\=x^4+x^2+1[/tex]
