Question

tìm n thuộc  N sao cho n+5 chia hết cho n+1

Answer 1

\(\Leftrightarrow n+1\in\left\{1;2;4\right\}\)

hay \(n\in\left\{0;1;3\right\}\)

Answer 2

\(\Leftrightarrow n+1+4⋮n+1\\ \Leftrightarrow4⋮n+1\\ \Leftrightarrow n+1\inƯ\left(4\right)=\left\{-4;-2;-1;1;2;4\right\}\\ \Leftrightarrow n\in\left\{-5;-3;-2;0;1;3\right\}\)