Giải:
Ta có:
\(5⋮n+3\Rightarrow n+3\in\left\{\pm1;\pm5\right\}\)
+) \(n+3=1\Rightarrow n=-2\)
+) \(n+3=-1\Rightarrow n=-4\)
+) \(n+3=5\Rightarrow n=2\)
+) \(n+3=-5\Rightarrow n=-8\)
Vậy \(n\in\left\{-2;-4;2;-8\right\}\)
Giải:
Ta có:
\(n+8⋮n+5\)
\(\Rightarrow\left(n+5\right)+3⋮n+5\)
\(\Rightarrow3⋮n+5\)
\(\Rightarrow n+5\in\left\{\pm1;\pm3\right\}\)
+) \(n+5=1\Rightarrow n=-4\)
+) \(n+5=-1\Rightarrow n=-6\)
+) \(n+5=3\Rightarrow n=-2\)
+) \(n+5=-3\Rightarrow n=-8\)
Vậy \(n\in\left\{-4;-6;-2;-8\right\}\)