Ta có 13n chia hết cho n-1
=> 13n-13+13 chia hết cho n-1
Do 13n-13=13(n-1) chia hết cho n
=>13 phải chia hết cho n-1
=> n-1thuộc {1;13;-1;-13}
=>n thuộc {2;14;0;-12}
Vậy n={2;14;0;-12}
tick nha
=>
h | |
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