Question

Tìm n ϵ N

a) (n + 3) ⋮ (n - 1)

b) 4n + 3 ⋮ 2n + 1

Answer 1

a) ta có: n+3 \(⋮\) n-1

n-1+4 \(⋮\) n-1

Vì n-1 \(⋮\) n-1 nên 4 \(⋮\) n-1.

\(\Rightarrow\) n-1 \(\inƯ\left(4\right)=\left\{1;2;4\right\}\)

\(\Rightarrow n\in\left\{2;3;5\right\}\)

Answer 2

b:=>4n+2+1 chia hết cho 2n+1

=>\(2n+1\in\left\{1;-1\right\}\)

=>\(n\in\left\{0;-1\right\}\)