\(A=\frac{3n-5}{n+4}=\frac{3\left(n+4\right)-17}{n+4}=3-\frac{17}{n+4}\)
Để A có giá trị nguyên => \(\frac{17}{n+4}\)có giá trị nguyên
=> \(17⋮n+4\)
=> \(n+4\inƯ\left(17\right)=\left\{-17;-1;1;17\right\}\)
| n+4 | -17 | -1 | 1 | 17 |
| n | -21 | -5 | -3 | 13 |
\(A=\frac{3n-5}{n+4}=\frac{3\left(n+4\right)-17}{n+4}=\frac{-17}{n+4}\)
\(\Rightarrow n+4\inƯ\left(-17\right)=\left\{\pm1;\pm17\right\}\)
Ta lập bảng
| n + 4 | 1 | -1 | 17 | -17 |
| n | -3 | -5 | 13 | -21 |
Cho cac bieu thuc
A=n+6 phan n-5 va B=3n-9 phan n-6
a/ Tim gia tri nguyen cua n de A, B la phan so ?
b/ Tim gia tri nguyen cua n de A, B co gia tri nguyen?
c/ Tim gia tri nguyen cua n de A, B co gia tri nguyen lon nhat?
Cho A=\(\frac{3n-5}{n+4}\).Tim n \(\in\)Z de A co gia tri nguyen
tim n de phan so A co gia tri nguyen
3n-5/n+4
cho phan so A= (6n- 1)/3n+2
tim n thuocZ de a co gia tri nguyen
tim n thuoc Z de a co gia tri lon nhat
5, Tim gia tri nguyen cua n de cac phan so sau co gia tri la so nguyen
\(A=\frac{3n+4}{n-1}\)
\(B=\frac{6n-3}{3n+1}\)
tim so nguyen n de A=3n+2chia cho n co gia tri la mot so nguyen
Cho A=3n-5/n+4. Tim n thuoc Z de A co gia tri nguyen.
Giai day du ho minh nhe! Cam on moi nguoi nhieu!
cho A=6n-1/3n+1(n thuoc z) hoi a tim n de A nguyen b tim n de A co gia tri nho nhat
tim tat ca cac gia tri nguyen cua n de phan so A=3n+2/n-1 co gia tri la so nguyen
