chung minh rang voi moi so tu nhien n # 0 thi:
a moi so nguyen to lon hon 2 deu co dang 4n _+1
b moi so nguyen t lon hon 3 deu co dang 6n +_1
chung minh rang moi so nguyen to lon hon 2 deu viet duoc duoi dang 4n+1 hoac 4n+3
Chung minh rang moi uoc nguyen to cua 1*2*3*.........*2002-1 deu lon hon 2002 ( vi ko co dau nhan neu thay bang dau sao nha )
cho P la so nguyen to lon hon e
a)chung to rang P co dang 6k+1hoac 6k+3
b)biet 8P+1va P deu la so nguyen to(Plon hon 3).Hoi P+100 ;a so nguyen to hay hop so
1) Mot so nguyen to chia cho 30 duoc so du la r.Tim r,biet r khong phai la so nguyen to.
2) Chung minh rang:
a/ So 17 khong viet duoc tong 3 hop so khong bang nhau.
b/Moi so le lon hon 17 deu viet duoc duoi dang 3 hop so khac nhau.
chung minh rang moi uoc nguyen to cua 2014!+1 deu lon hon 2014
Chung minh rang moi phan so dang n+1/2n+3 ( n thuoc N ) deu la phan so toi gian.
cach lam bai : chung to rang moi phan so co dang n+2015/n+2016 ( voi n thuoc N ) deu la phan so toi gian
1)chung to rang so nguyen to p;p>5 khi chia cho 6 chi co the du 1 hoac 5
2)chung minh rang neu p va p+2 la so nguyen to lon hon 3 thi p+1 la mot hop so
cac an giai giup minh minh dang can gap
ai giai nhanh minh tick cho