Question

5 \(⋮\)n+3

n+8 \(⋮\)n+5

( làm nhanh nha )

Answer 1

a)5 chia hết n+3

=>n+3 thuộc Ư(5)={1;-1;5;-5}

=>n thuộc {-2;-4;2;-8}

b)\(\frac{n+5+3}{n+5}=\frac{n+5}{n+5}+\frac{3}{n+5}=1+\frac{3}{n+5}\in Z\)

=>3 chia hết n+5

=>n+5 thuộc Ư(3)={1;-1;3;-3}

=>n thuộc {-4;-6;-2;-8}

Answer 2

a)

5 chia het cho n+3

=> n+3 ϵ U(5)

=> n+3 ϵ { 1,5,(-1),(-5) }

=> n ϵ { (-2), 2, (-4), (-8) }

b)

n+8 chia het cho n+5

=> n+8-n-5 chia het cho n+5

=> 3 chia het cho n+5

=> n+5 ϵ U(3)

=> n+5 ϵ { 1,3,(-1), (-3) }

=> n ϵ { (-4), (-2), (-6), (-8) } 

Answer 3

5 chia hết cho n + 3

=> n + 3 thuộc Ư(5)

=> Ư(5) = {1;-1;5;-5}

=> n = {-2;-4;2;-8}

n + 8 chia hết cho n + 5

<=> n + 5 + 3 chia hết cho n + 5

=> n + 5 thuộc Ư (3) = {1;-1;3;-3}

=> n = {-4;-6;-2;-8}

Answer 4

Giải:

Ta có:
\(5⋮n+3\Rightarrow n+3\in\left\{\pm1;\pm5\right\}\)

+) \(n+3=1\Rightarrow n=-2\)

+) \(n+3=-1\Rightarrow n=-4\)

+) \(n+3=5\Rightarrow n=2\)

+) \(n+3=-5\Rightarrow n=-8\)

Vậy \(n\in\left\{-2;-4;2;-8\right\}\)

Giải:

Ta có:

\(n+8⋮n+5\)

\(\Rightarrow\left(n+5\right)+3⋮n+5\)

\(\Rightarrow3⋮n+5\)

\(\Rightarrow n+5\in\left\{\pm1;\pm3\right\}\)

+) \(n+5=1\Rightarrow n=-4\)

+) \(n+5=-1\Rightarrow n=-6\)

+) \(n+5=3\Rightarrow n=-2\)

+) \(n+5=-3\Rightarrow n=-8\)

Vậy \(n\in\left\{-4;-6;-2;-8\right\}\)