a)
Khi đó \(n-4\in\left\{1;11;-1;-11\right\}\)
=> \(n\in\left\{5;15;3;-7\right\}\)
Vậy \(n\in\left\{-7;3;5;15\right\}\)
b)
Có: \(n+5⋮n-2\)
=> \(\left(n-2\right)+7⋮\left(n-2\right)\)
=> \(7⋮\left(n-2\right)\)
=> \(n-2\in\left\{1;-1;7;-7\right\}\)
=> \(n\in\left\{3;1;9;-5\right\}\)
a) Có: n - 4 là ước của 11
\(\Rightarrow n-4\in\left\{\pm1;\pm11\right\}\)
\(\Rightarrow n\in\left\{5;3;15;-7\right\}\)
Vậy \(n\in\left\{5;3;15;-7\right\}\).
b) Có: \(n+5⋮n-2\)
\(\Rightarrow n-2+7⋮n-2\)
\(\Rightarrow7⋮n-2\)
\(\Rightarrow n-2\inƯ\left(7\right)=\left\{\pm1;\pm7\right\}\)
\(\Rightarrow n\in\left\{3;1;9;-5\right\}\)
Vậy \(n\in\left\{3;1;9;-5\right\}\).
a) n - 4 là ước của 11
\(\Rightarrow n-4\inƯ\left(11\right)=\left\{-1;-11;1;11\right\}\)
\(\Rightarrow n=\left\{3;-7;5;15\right\}\)
b) \(n+5⋮n-2\)
\(n-2+7⋮n-2\)
vì \(n-2⋮n-2\)
\(\Rightarrow7⋮n-2\)
\(\Rightarrow n-2\inƯ\left(7\right)=\left\{-1;-7;1;7\right\}\)
\(\Rightarrow n=\left\{1;-5;3;9\right\}\)
a) n - 4 là ước của 11
=> n - 4 = { -11 ; -1 ; 1 ; 11 }
=> n = { -7 ; 3 ; 5 ; 15 ]
b) n + 5 chia hết cho n - 2
=> ( n - 2 ) + 7 chia hết cho n - 2
=> 7 chia hết cho n - 2
=> n - 2 thuộc Ư(7) = { -7 ; -1 ; 1 ; 7 }
=> n = { -5 ; 1 ; 3 ; 9 }
a, \(n-4\inƯ\left(11\right)=\left\{\pm1;\pm11\right\}\)
| n - 4 | 1 | -1 | 11 | -11 |
| n | 5 | 3 | 15 | -7 |
b, \(n+5⋮n-2\Leftrightarrow n-2+7⋮n-2\)
\(\Leftrightarrow7⋮n-2\Leftrightarrow n-2\inƯ\left(7\right)=\left\{\pm1;\pm7\right\}\)
| n - 2 | 1 | -1 | 7 | -7 |
| n | 3 | 1 | 9 | -5 |
