bai 1:tim n thuoc n de:3(n+2) chia het cho n-2
bai 2chng minh rang cac so sau la cac so nguyen to cung nhau
a) 18n+3 va 21n+4
b)2n+1va3n+1
bai 3:tim hai so biet tong hai so la 90 va uoc chung lon nhat la 15
bai 4:tim so tu nhien n lon nhat co 3 chu so sao cho n :15 du 9va n:35 du 29
bai 5:tim uoc chung lon nhat cua cac so sau:
a)18n+3 va 21n+4
b)9n+13 va 3n+4
bai 6:chung minh: voi moi a,b thuoc nta co
UCLN(a,b)=UCLN (5a+2b,7a+3b)
AI DUNG TRUOC 9H MINH SE TICH CHO.THANHK YOU VERY MUCH!
chung minh voi moi STN n cac so sau la 2 so nguyen to cung nhau
2n+3 va 4n+8
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 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
ai giup minh voi
chung to rang 2 so n+1 va 3n+1{n thuoc N} la 2 so nguyen to cung nhau
minh dang can gap...................''''
chung minh rang so 2n+1 va 6n+5 nguyen to cung nhau voi moi so tu nhien n
Chung minh cac phan so sau la phan so toi gian voi moi so nguyen n :A=12n+1 tren 30n+2
Giúp mình bài này :
Chung minh rang 2 so 2n+3 va 3n+4 voi n thuoc N la 2 so nguyen to cung nhau
