Các câu hỏi tương tự
Cho so a= 36.q + 15 voi q la so tu nhien
A. Chung to rang a khong chia het cho 2
B. Chung to rang a chia het cho 3 va a khong phai la so nguyen to
Voi n la so tu nhien, cho: A=20134n(2013(4n+3)-1)-1. Chung minh rang A 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.
Cho a va b la hai so nguyen to lon hon 2 . Chung minh : P=a+b khong phai la so nguyen to
tong tat ca cac so nguyen to co dang 13a(chu y so tren la so co dang 13a chu khong phai 13 nhan a)
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
Cho n>2 va n khong chia het cho 3. Chung minh rang n^2-1 va n^2+1khong phai so nguyen to
chung minh rang hai so 2009^100-1va 2009^100+1 khong dong thoi la so nguyen to
cho p la tich cua 2016 so nguyen to dau tien
chung minh rang p-1 va p+1 khong la so chinh phuong