4n+14⋮n+1
4(n+1)+10⋮n+1
⇒10⋮n+1\(\left\{\left(4\left(n+1\right)\right)\text{⋮}n+1\right\}\)
⇒n+1∈ Ư(10)=\(\left\{1,2,5,10\right\}\)
⇒n∈\(\left\{0,1,4,9\right\}\)
Câu này làm rồi em nhé
https://hoc24.vn/cau-hoi/tim-so-tu-nhien-n-sao-cho4n14n1.1892748799601
(4n+14)⋮(n+1)(4n+14)⋮(n+1)
⇔4(n+1)+10⋮(n+1)⇔4(n+1)+10⋮(n+1)
⇔(n+1)∈Ư(10)={1;−1;2;−2;5;−5;10;−10}⇔(n+1)∈Ư(10)={1;−1;2;−2;5;−5;10;−10}
Do n∈Nn∈N
⇔n∈{0;1;4;9}