Question

​​Tìm n € N biết

3n+1chia hết cho n-3

 

 

Answer 1

1 day nha

Answer 2

n = 5 vì :

    => 3.5 + 1 : 5 - 3

    = 15 + 1 : 5 - 3

    = 16 : 2

    = 8

=> n = 5 vì 3.5 + 1 CHC 5 - 3 .

Answer 3

\(\frac{3n+1}{n-3}=\frac{3n-9+10}{n-3}=\frac{3.\left(n-3\right)+10}{n-3}=\frac{3.\left(n-3\right)}{n-3}+\frac{10}{n-3}=3+\frac{10}{n-3}\)

Mà 3 \(\in N\Rightarrow n-3\inƯ\left(10\right)\)

\(\Rightarrow n-3\in\left\{1;2;5;10\right\}\Rightarrow n\in\left\{4;5;8;13\right\}\)