Question

Tin so nguyen n biet rang : n-4 chia het cho n-1

Answer 1

ta có: n - 4 \(⋮\)n - 1

=> ( n - 1 ) - 3  \(⋮\)n - 1

=> 3  \(⋮\)n - 1

=>  n - 1 \(\in\){ -3;-1;1;3 }

=> n \(\in\){ -2;0;2;4 }

vậy:  n \(\in\){ -2;0;2;4 }

HAPPY NEW YEAR.

Answer 2

n - 4 ⋮ n - 1

<=> (n - 1) - 3 ⋮ n - 1

<=> 3 ⋮ n - 1

Hay n - 1 ∈ Ư(3( = { ± 1; ± 3 }

Ta có bảng sau :

n - 1	- 3	- 1	1	3
n	- 2	0	2	4

Vậy n = { - 2; 0; 2; 4 }