Question

(u^2+2u+2)*(u^2-2u+2)=?

Answer 1

$(u^{2}+2u+2)(u^{2}-2u+2)=((u^{2}+2)+2u)((u^{2}+2)-2u)=(u^{2}+2)^{2}-(2u)^{2}=\\=u^{4}+4u^{2}+4-4u^{2}=u^{4}+4$

Answer 2

(u^2+2u+2)*(u^2-2u+2) = u^4 - 2u^3 + 2u^2 + 2u^3 - 4u^2 + 4u + 2u^2 - 4u + 4 = u^4 + 2u^2 + 4u + 4