cho hai phan so C=2/n-1 va D=n+4/n+1 .tap hop cac so nguyen "n" de C va D deu la cac so nguyen la?

.mk dang can gap ai nhanh nhat mk tick cho

1) Tim so nguyen to P de co: 

a) P+10 va P+14 deu la so nguyen to

b) P+2 ;P+6 va P+8 deu la so nguyen to

Bai 1:tim so nguyen P biet P+2va P+4 deu la nguyen to

bai 2: tong 2^100×7×11+81^3  la nguen to hay hop so ( giai thich)

Bai 3: tim so nguyen to P de P +2,p+6,P+8 deu la cac so nguyen to

tim giao cua 2 tap hop A va B biet rang:

    a , A la tap hop cac so chia het cho 24 , B la tap hop cac so chia het cho 120

     b, A la tap hop cac so chan, B la tap hop cac so nguyen to

1)Viet tap hop B gom can so la tich cua dung 3 so Nguyen to co 1 chu so 

2) Viet tap hop A gom cac so chan co 4 chu so va co tich cac chu so bang 10

tap hop cac so tu nhien n de 5^n+30 la so nguyen to 

n={...}

cho p la so nguyen to lon hon 3. Biet 8p+1 va p deu la so nguyen to (p lon hon 3).Hoi p+100 la so nguyen to hay hop so

tim so nguyen to p de p+10, p+14 deu la so nguyen to