Question

tìm \(n\in z\)

n - 3\(⋮\) n + 2

Answer 1

\(n-3⋮n+2\)

\(\Rightarrow n-3=n+2-5\)

Vì \(n+2⋮n+2\) để \(n-3⋮n-2\) thì \(5⋮n-2\)

\(n+2\in U\left(5\right)\)

Ư(5) = \(\left\{\pm1;\pm5\right\}\)

Ta có :

n+2 = 1 => n = -1(tm)

n + 2 = -1 => n = -3 (tm)

n + 2 = 5 => n = 3 (tm)

n + 2 = -5 => n = -7 (tm)

Vậy ...