chung minh rang voi moi so tu nhien n, cac so sau la hai so nguyen to cung nhau:
a) 7n + 10 va 5n + 7
b) 2n +3 va 4n +8
Chung minh rang voi moi so n thi 2 so sau nguyen to cung nhau
2n+5 va 2n+7
2n+5 va 3n+8
5n+7 va 2n+3
chung minh rang n+1 va 2n+3 la 2 so nguyen to cung nhau
Chung to rang hai so 2n+7 va 2n+9 la hai so nguyen to cung nhau
chung minh 2n +5 va 3n + 7 la 2 so nguyen to cung nhau
giai chi tiet nha
ai nhanh like luon
chung to rang voi moi so tu nhien N gia tri cua 2 bieu thuc 7n+10 va 5n+7 luon la 2 so nguyen to cung nhau
Chung to rang cac so sau la cac so nguyen to cung nhau :
1) 2n + 1 và 2n + 3
2) 2n + 5 va 3n + 7
chung minh rang 2n+3 va 3n+5 la hai so nguyen to cung nhau (n thuoc N*)
chung minh voi moi STN n cac so sau la 2 so nguyen to cung nhau
2n+3 va 4n+8
