Ta có : \(A=\frac{2n-1}{n+3}=\frac{2n+6-7}{n+3}=\frac{2\left(n+3\right)}{n+3}-\frac{7}{n+3}=2-\frac{7}{n+3}\)
Để \(A\in Z\) thì 7 chia hết cho n + 3
Suy ra n + 3 thuộc Ư(7) = {-7;-1;1;7}
Ta có bảng ;
| n + 3 | -7 | -1 | 1 | 7 |
| n | -10 | -4 | -2 | 4 |
Cho A = \(\frac{n-1}{n-3}\)(n Khac 0)
a) Tim n thuoc Z de A thuoc Z
b) Tim n thuoc Z de A co gia tri
Cho phan so A = 2n + 9/n + 3. Tim n de A thuoc Z
tim n thuoc z de phan so sau a=4n-1/2n+3 co gia tri nguyen
Cho phan so: P = \(\frac{2n+7}{5n+2}\)(n thuoc Z)
a)Tim n thuoc z de P la phan so chua toi gian.
b)Tim n thuoc Z sao cho P la phan so toi gian.
cho A=n+3\n-2 (n thuoc Z)
a) tim n de A la phan so
b) tim n de A thuoc Z
c) tim n biet A=-4
Cho phan so A=n+10/2n-8 tim so n de A thuoc Z
tim n thuoc Z de : 2n-1 chia het cho n-2
tim n thuoc z de
a) n+7 chia het n+1
b) 2n-1 chia het n-2
Cau 1 .Tim n thuoc N de 2n + 5 / 3N +1 THUOC Z
Cau 2 . C = 1/11 + 1/12 + 1/13 +… + 1/70chung to C lon hon 4/3
