chung minh rang:
tong hoac hieu cua mot so tn voi mot phan so toi gian la mot phan so toi gian
Chung minh cac phan so sau la phan so toi gian voi moi so nguyen n :A=12n+1 tren 30n+2
chung to rang voi moi so nguyen n phan so 3n-5/3-2nla phan so toi gian
chung minh rang : Voi moi n thi phan so 7n+4/5n+3 la phan so toi gian .
Giup to bai nay voi : Chung minh voi n thuoc N sao phan so sau la phan so toi gian 4n+1/6n+1
cho a va b la hai so nguyen to cung nhau chung minh rang a^2+b^2/a.b la phan so toi gian
tinh tong cac phan so toi gian khong la so tu nhien co mau 11 lon hon 12 va nho hon 35
giup toi voi
Chung to rang 12n+1phan 30n+2 la phan so toi gian
chung minh: Voi moi n thi phan so 7n+4/5n+3la phan so toi gian