Cho hai so nguyen to cung nhau la a,b .
CMR hai so 11a+2b va 18a+5b thi hoac nguyen to cung nhau hoac co mot uoc chung la 19.
1)n+1 va 3n+4 la nguyen to cung nhau
2)2n+3 va 4n+8 la 2 so nguyen to cung nhau
cho a va b la 2 so nguyen to cung nhau chung minh rang cac so sau cung la 2 so nguyen to cung nhau 1) a va a+b 2) a va a-b
1) Biet rang 996 va 632 khi chia cho n deu du 16 . Tim n.
2) Chung minh rang 7n + 10 va 5n + 7 la hai so nguyen to cung nhau ( n thuoc N )
3) Biet rang 7a + 2b chia het cho 13 (a,b thuoc N) . Chung minh rang 10a + b cung chia het cho 13
voi 2 so nguyen to cung nhau neu 2 so nguyen to cung nhau co tich va so ching phuong thi 2 so deu la so chinh phuong
cho a va b la hai so nguyen to cung nhau chung minh rang a^2+b^2/a.b la phan so toi gian
cho a la so tu nhien le b la so tu nhien chung minh rang so a va ab + 4 la 2 so nguyen to cung nhau
cho a+ b = p la snt . chung to rang a va b la hai so nguyen to cung nhau . minh can gap
tim so nguyen to ab co 2 chu so khac nhau sao cho ba cung la 1 so nguyen to va ab - ba la 1 so chinh phuong
