Gọi d là \(UCLN\left(2n+3;n+2\right)\)
\(\Rightarrow\left\{{}\begin{matrix}2n+3⋮d\\n+2⋮d\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}2n+3⋮d\\2n+2⋮d\end{matrix}\right.\)
\(\Rightarrow\left(2n+3\right)-\left(2n+2\right)⋮d\)
\(1⋮d\Rightarrow d=1\)
Vậy p/s \(\dfrac{2n+3}{n+2}\) tối giản với mọi \(n\in N\)