M = 2a + 8/5 - a - 7/5 = a +1/5 = (5a+1)/5
Để M nguyên khi và chỉ khi 5a+1 chia hết cho 5 hay 5a+1 là bội của 5
a={ -1/5; 4/5; -6/5;9/5; -11/5;...) hay a = (5n- 1)/5 với n thuộc Z
tim so nguyen a de bieu thuc sau co gia tri la so nguyen : M=(2a+8):5+(-a-7):5
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?
a) Tim so nguyen n de bieu thuc de n-1 la uoc cua 5
b) Tim so nguyen m de bieu thuc : A = -5/m-1 co gia tri nguyen voi n khong =1
Chu y :may ban lam 2 cau ruj minh tick cho ha
A=n-1/n+2
a, Voi gia tri nao thi A la phan so
b, Tim so nguyen n de A=0
c,tim so nguyen n de A co gia tri nguyen
Cho A=n+3/n+2 voi n€z
a)tim dieu kien cua so nguyen n de A la phan so
b)tinh gia tri cua phan so A khi n=1;n=-1
c)tim so nguyen n de phan so A co gia tri la so nguyen
tim tat ca cac gia tri nguyen cua n de phan so A=3n+2/n-1 co gia tri la so nguyen
tim so nguyen n de phan so 4n+5/2n-1 co gia tri la mot
so nguyen
tim gia tri nguyen n de phan so M=2n-7/n-5 co gia tri nguyen
viet ca cach giai nhe
pp
tim so nguyen n de A=3n+2/n co gia tri la mot so nguyen