Raspuns:
([tex]x^{2} [/tex] +[tex]x[/tex] -1)([tex]x^{2} [/tex] -2x +1)=
[tex]= x^{4} - 2x^{3} +x^{2} +x^{3} -2x^{2} +1-x^{2} +2x-1=\\ =x^{2} -x^{3} -2x^{2} +3x-1[/tex]
Formula de calcul:
[tex](x^{2} +x-1) ==> (a+b)^{2} [/tex]
[tex](x^{2} -2x+1) ==> (a-b)^{2} [/tex]