Question

ПОМОГИТЕ!!!

1) (n+7)*(-n-4)=
2) (13p-1)(13p+4)=
3)$(a+b)( a^{2}-ab+ b^{2})=$

Answer 1

$1) (n+7)(-n-4)=-n^2-4n-7n-28=-n^2-11n-28 \ \ 2)(13p-1)(13p+4)=169p^2+52p-13p-4=169p^2+39p-4 \ \ 3)(a+b)(a^2-ab+b^2)=a^3+b^3$