tim so tu nhien n sao cho 7n+13 va 2n+4 la nguyen to cung nhau
voi n so tu nhien thoa man 6n+1 va 7n-1 la hai so tu nhien khong nguyen to cung nhau thi uoc chung lon nhat cua 6n+1 va 7n-1 la bao nhieu
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
BAI 1: TIM SO TU NHIEN N DE MOI CAP SO SAU LA SO NGUYEN TO:
A, 7N+13 VA 2N+4
B, 12N+5 VA 9N+4
BAI 2: TIM * DE (81**)CHIA HET CHO 6;7;13
PLEASE GIUP MK.........
CMR:co vo so so tu nhien n de n +15 va n+72 la hai so nguyen to cung nhau.
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
tim so tu nhien n de cac so 9n+24 va3n+4 la cac so nguyen to cung nhau
chung to rang hai so 3n+4 va n+1 la hai so nguyen to cung nhau voi n la so tu nhien khac 0
tim n thuoc N de cac ap so sau nguyen to cung nhau
a) 3n + 2va 7n+1
b) 2n+7 va 5n+2