Các câu hỏi tương tự
Voi n la so tu nhien, cho: A=20134n(2013(4n+3)-1)-1. Chung minh rang A khong phai la so nguyen to.
chung minh rang so111...12111...1tat ca co50 chu so1 .khong phai la so nguyen to.
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.
Chung minh rang: moi n thuoc z ( n khac 0,n khac -1) thi : Q =1\1.2+1\2.3+1\3.4+......+1\n(n+1) khong phai la so nguyen
1/12+1/122+1/32+1/42+...+1/n2 chung to phep tinh tren khong phai la so nguyen
So (-3)^20+1 co phai la tich cua 2 so nguyen lien tiep khong?
chung minh rang tong sau khong phai la so tu nhien
1/2+1/3+1/4+1/5+1/6+...+1/16
chung minh rang A = 1/2 + 1/3 + 1/4 +...+ 1/50 khong phai la so tu nhien
1/. X36y chia het cho 9, biet y là so nguyen to nho nhat?
2/. 6x3y chia het cho 3 , khi chia 5 dư 1
3/. x63y chia het cho 3, biet x khong phai la so nguyen to, cung khong phai la hop so