Question

Tìm số tự nhiên x sao cho (x+2)chia hết cho (x+1)

Answer 1

Ta có :

\(x+2⋮x+1\)

\(x+1⋮x+1\)

\(\Rightarrow\left(x+2\right)-\left(x+1\right)⋮x+1\)

\(x+2-x-1⋮x+1\)

\(1⋮x+1\)

\(\Rightarrow x+1\in\text{Ư}\left(1\right)=\left\{1;-1\right\}\)

\(\Rightarrow x=\left\{0;-2\right\}\)