Ta có:
\(n+2⋮2n+1\Rightarrow2\left(n+2\right)⋮2n+1\Rightarrow\left(2n+4\right)⋮\left(2n+1\right)\)
\(\Rightarrow\left(2n+1+3\right)⋮\left(2n+1\right)\)
Do \(\left(2n+1\right)⋮\left(2n+1\right)\Rightarrow3⋮\left(2n+1\right)\Rightarrow2n+1=Ư\left(3\right)=\left\{1;3\right\}\)
\(\Rightarrow\left[{}\begin{matrix}2n+1=1\\2n+1=3\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}2n=0\\2n=2\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}n=0\\n=1\end{matrix}\right.\)
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