Question

[Hải Linh]

9) n2 + 3n +3 ⋮ n +1

10) n2 + 4n + 2 ⋮ n +2

11)n2 - 2n + 3 ⋮ n - 1

Tìm n e Z

Answer 1

[Nguyễn Lê Phước Thịnh]

9: \(\Leftrightarrow n^2+n+3n+2+1⋮n+1\)

\(\Leftrightarrow n+1\in\left\{1;-1\right\}\)

hay \(n\in\left\{0;-2\right\}\)

10: \(\Leftrightarrow n^2+4n+4-2⋮n+2\)

\(\Leftrightarrow n+2\in\left\{1;-1;2;-2\right\}\)

hay \(n\in\left\{-1;-3;0;-4\right\}\)

11: \(\Leftrightarrow n^2-2n+1+2⋮n-1\)

\(\Leftrightarrow n-1\in\left\{1;-1;2;-2\right\}\)

hay \(n\in\left\{2;0;3;-1\right\}\)