Question

Tìm số nguyên n biết

3n-5 chia hết n-2

Answer 1

3n + 5 ⋮⋮ n - 2

$\iff$ 3n - 6 + 1 ⋮⋮ n - 2

$\iff$ 3(n - 2) + 1 ⋮⋮ n - 2

$\iff$ 1 ⋮⋮ n - 2

$\iff$ n - 2 $\in$ Ư(1) = $\left\{-1;1\right\}$

$\iff$$[\begin{array}{c}n-2=-1\Rightarrow n=1\\ n-2=1\Rightarrow n=3\end{array}$

Answer 2

⇔n−2∈Ư(1)⇔n−2∈Ư(1)