Đáp án:
a. \(\left[ \begin{array}{l}
n = 4\\
n = - 2\\
m = 2\\
n = 0
\end{array} \right.\)
b. \(\left[ \begin{array}{l}
n = 3\\
n = 1
\end{array} \right.\)
Giải thích các bước giải:
\(\begin{array}{l}
a.n + 2 \vdots n - 1\\
\Leftrightarrow n - 1 + 3 \vdots n - 1\\
\Leftrightarrow 3 \vdots n - 1\\
\to n - 1 \in U\left( 3 \right)\\
\to \left[ \begin{array}{l}
n - 1 = 3\\
n - 1 = - 3\\
n - 1 = 1\\
n - 1 = - 1
\end{array} \right. \to \left[ \begin{array}{l}
n = 4\\
n = - 2\\
m = 2\\
n = 0
\end{array} \right.\\
b.3n - 5 \vdots n - 2\\
\to 3\left( {n - 2} \right) + 1 \vdots n - 2\\
\Leftrightarrow 1 \vdots n - 2\\
\Leftrightarrow n - 2 \in U\left( 1 \right)\\
\to \left[ \begin{array}{l}
n - 2 = 1\\
n - 2 = - 1
\end{array} \right. \to \left[ \begin{array}{l}
n = 3\\
n = 1
\end{array} \right.
\end{array}\)
