Vậy: a+b = 3+7
Chứng minh: P=a+b => 3+7= 10
Mà 10 là hợp số
Vậy: a+b = 3+7
Chứng minh: P=a+b => 3+7= 10
Mà 10 là hợp số
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.
Cho P la so nguyen to lon hon 3 va 5p+1 cung la so nguyen to. Chung minh rang 7p+1 la hop so
Cho so a= 36.q + 15 voi q la so tu nhien
A. Chung to rang a khong chia het cho 2
B. Chung to rang a chia het cho 3 va a khong phai la so nguyen to
cho A = 1+2+3+4+...+n va B = 2n + 1 ( voi n thuoc N , n lon hon hoac bang 2) chung minh A va B la hai so nguyen to cung nhau
cho p la so nguyen to lon hon 3
a] chung to rang p 6k+1 hoac 6k+5
b] biet 8p +1 la so nguyen to chung minh 4p+1 la hop so
cho n la so nguyen to lon hon 3. hoi n^2 la nguyen to hay hop so. ai lam loi giai va lam dung la duoc tich
cho dap an la hop so nhung phai lam cach lam
chung to rang so nguyen to p;p>5 khi chia cho 6 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
Cho p va 10p+1 la cac so nguyen to lon hon 3. Chung minh 17p+1 la hop so
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