cho a la 1 hop so, khi phan tich ra thua so nguyen to chi chua hai thua so nguyen to khac nhau la P 1 va P 2. biet a^3 co tat ca 40 uoc. Hoi a ^2 co bao nhieu uoc

Cho H=111...1(2012 chu so 1)

Hoi H la so nguyen to hay hop so?

11111 co phai la so nguyen to khong .neu la hop so thi hay phan tich ra thua so nguyen to

Cho A= 2222.....22000...000111...11(co 100 chu so 2, 100 chu so 0 , 100 chu so 1 )

Hoi A la so nguyen to hay hop so ? taisao?

 cho a la mot hop so ,khi phan tich ra thua so nguyen to chi chua 2 thua so nguyen to khac nhau la p₁ va p₂.biet a³ co tat ca 40 uoc hoi a²co bao nhieu uoc 

a, tim so tu  nhien trong khoang tu 100 den 300 biet rang so do chia cho 4 cho 5 cho 6 deu du 2 nhung so do lai chia het cho 11

b, dung ba chu so 1 ; 2 ; 3 hay viet tat ca cac so tu n hien co ba chu so ma cac chu so khac nhau , chung to rang tat ca cac so tu nhien do dau la hop so

c, tim so tu nhien nho nhat cho bon chu so giong nhau biet rang so do co dung ba uoc deu la o nguyen to

Cho a la mot hop so.biet khi phan tich ra thua so nguyen to thi a chi chua 2 thua so nguyen to la p1 va p2. Biet a mu 3 co tat ca 40 uoc tu nhien.

Hoi a mu 2 co bao nhieu uoc tu nhien.

Ai giai nhanh minh tick.giai ra nhe

tong tat ca cac so nguyen to co dang 13a(chu y so tren la so co dang 13a chu khong phai 13 nhan a)

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