Question

Gente me ajuda pelo amor de Deus,pra hoje

Answer 1

$(x^2-y^2)^2=(x^2)^2-2\cdot x^2\cdot y^2+(y^2)^2=x^4-2x^2y^2+y^4$

$-(x^2+y^2)\cdot(x^2-y^2)=-[(x^2)^2-(y^2)^2]=-(x^4-y^4)=-x^4+y^4$

Substituindo:

$\texttt{E}=(x^2-y^2)^2-(x^2+y^2)\cdot(x^2-y^2)+2x^2y^2$

$\texttt{E}=x^4-2x^2y^2+y^4-x^4+y^4+2x^2y^2$

$\texttt{E}=2y^4$

Letra A