Cho a=3^2009.7^2010.13^2011.So du cua a khi chia cho 10 la
cho 1 so co 2 chu so biet khi ta bo chu so hang don vi cua so lon thi ta duoc so be va so lon bang 10 lan so be. Tim 2 so do
Tim chu so hang don vi cua tong M=172012+112012-72012
bai 1 tim cac stn x y z sao cho x+y+z=xyz
bai 2cmr neu m^2+mn+n^2chia het cho 9 voi m ,n la cac stn thi m,n chia het cho 3
bai 3 tim stn n nho nhat de cac phan so sau toi gian
7/n+9.8/n+10,...,31/n+33
bai 4chung to rang phan so m^3+2m/m^4+3m^2 +1 toi gian
bai 5 a,cmr khong ton tai so chinh phuong nao co dang abab
b,cho 51 so nguyen duong khong vuot qua 100 cmr ton tai 2 so trong 51 so noi tren ma 1 so chia het cho so con lai
c,tim cac so co 3 chu so sao cho hieu cua so ay va gom 3 chu so ay viet theo thu tu nguoc lai la mot so chinh phuong
bai 6cmr A=2x(x+y-1)+y^2+1 luon nhan gia tri khong am voi moi x,y
bai 7 tim hai so nguyen duong sao cho tong ,hieu thuong (so lon chia cho so nho )cua chung cong lai duoc 38
bai 8 cho ba so a,b,c thoa man a/2009=b/2010=c/2011
tinh gia tri cua bieu thuc M=4(a-b)(b-c)-(c-a)^2
tim so co 4 chu so biet chu so hang nghin,chu so hang tram,chu so hang chuc,chu so hang don vi ti le voi 2;1;2;3 va so do chia het cho 3
tim mot so tu nhien co hai chu so biet rang so do bang lap phuong cua so tao boi chu so hang van va chu so hang ngan cua so da cho
tim mot so co 3 chu so biet rang neu tang chu so hang tram them n don vi giam chu so hang chuc va don vi di n don vi ta duoc 1 so co 3 chu so gapn lan chu so ban dau
cho so a =2^13 x 5^7 tim so cac chu so cua a
giai chi tiet
cmr mot so có 2 chu so chia het cho 7 khi và chi khi tong cua chu so hang chuc va 5 lan chu so hàng don vi chia het cho 7
( ai lam duoc thi minh se dung tat ca cac nick minh co tick , bao gom ca nick nay nhung phai nhanh trươc mung 5 Tet )