Question

[phan thi ngoc mai]

Tìm số tự nhiên n biết:

a) 15⋮(n+1)

b) (n+3)⋮(n+1)

Answer 1

[ng.nkat ank]

a) 15 ⋮ 1 , 3 , 5, 15

Vậy n = 0 , 2 , 4 , 14

Answer 2

[Lấp La Lấp Lánh]

a) \(\Rightarrow\left(n+1\right)\inƯ\left(15\right)=\left\{-15;-5;-3;-1;1;3;5;15\right\}\)

Do \(n\in N\)

\(\Rightarrow n\in\left\{0;2;4;14\right\}\)

b) \(\Rightarrow\left(n+1\right)+2⋮\left(n+1\right)\)

Do \(n\in N\Rightarrow\left(n+1\right)\inƯ\left(2\right)=\left\{1;2\right\}\Rightarrow n\in\left\{0;1\right\}\)