Cho p la SNT > 3 va p+8 cung la SNT Hoi p+10 la snt hay hs
n>2.CMR NEU N CHIA HET CHO 3 THI N MU 2 TRU 1 VA N MU 2 CONG 1 KO DONG THOI CUNG LA SO NGUYEN TO
Tim stn n de n+1 va n-3 la 2 snt cung nhau
1.a. thay chu so thich hop vao dau *de dc hop so: *27
bphan tich cac hop so da tim dc ra thua so ng to
c. tim x thuoc N, biet:
c1: 327 chia het cho x
c2: 327la boi so cua x+12
c3: 327 chia het cho (2.x)
c. tim a,b thuoc N, a<b biet a.b=327
4. a) tong cua 25 SNT nho hon 100 la so chan hay so le?
b) tong cua 2 so NT co the = 999 dc ko? vi sao?
c) tong cua 2 so NT co the = 2007 dc ko? vi sao?
d) tong cua 3 so NT = 1012. tim so nho nhat
ban nao tra loi dung va chi tet minh cho 1 like
ne mik noi ne SNT la so nguyen to
thoi thi giai dung cau naao cung dc minh cung cho like
Cho a va b la 2 so nguyen to cung nhau
CMR:5a+2b va 7a=3b cung la 2 nso nguyen to cung nhau
CMR neu 2n-1 la SNT [ n>2] thi 2n+1 la HS
cho a+ b = p la snt . chung to rang a va b la hai so nguyen to cung nhau . minh can gap
cmr neu ps 7n2+1/6 la so tu nhien voi n la so tu nhien thi cac ps n/2 va n/3 la cac ps toi gian
CMR: Neu phan so 7n^2+1/6 la so tu nhien voi n thuoc N thi cac phan so n/2 va n/3 la cac phan so toi gian