Các câu hỏi tương tự
1) Mot so nguyen to chia cho 30 duoc so du la r.Tim r,biet r khong phai la so nguyen to.
2) Chung minh rang:
a/ So 17 khong viet duoc tong 3 hop so khong bang nhau.
b/Moi so le lon hon 17 deu viet duoc duoi dang 3 hop so khac nhau.
Mot so nguyen to chia cho 30 co so du la r. Tim r biet r khong phai la so nguyen to.
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Mot so nguyen to p khi chia cho 30 duoc so du r; r khong phai la so nguyen to.Tim p va r.
1so nguyen to chia cho 30 co so du la r tỉm r biet r ko phai la so nguyen to
cmr mot so nguyen to khi chia cho 30 co so du la 1 hoac mot so nguyen to
chung to rang so nguyen to p;p>5 khi chia cho 6 co the du 1 hoac 5
2)chung minh rang neu p va p+2 la so nguyen to lon hon 3 thi p+1 la mot hop so
cho a, b la 2 so nguyen khong la boi cua 3 nhung co cung so du khi chia cho 3.Chung to rang (ab-1) chia het cho 3
1 so nguyen to p chia cho 42 co so du r la hop so. Tim so du r
Tim so nguyen to <200, biet rang khi chia no cho 60 thi so du la hop so