Tim stn a chia 29 du 5 , chia 31 du 28
a . Tim stn a nho nhat thoa man db
b. So do chia 889 du may
c . Tim cac so tu 2000 - 3000 thoa man db
cho cac so nguyen duong a,b,c,d thoa man ab=cd. chung minh A=an + bn + cn + dn la mot hop so voi moi so tu nhien n
a, ab = 360 va BCNN[ a;b] = 60
b, UCLN[a:;b] =12 va BCNN[a;b] = 72
c, UCLN[a;b] = 15 va BCNN[a;b]=2100.UCLN[a;b]
1. cho 4 stn a lon hon hoac bang b, b lon hon hoac bang c, clon hon hoac bang d.
CM:(a-b)(a-c)(a-d)(b-c)(b-d)(c-d)
2. CM: co the tim dc 1 stn k sao cho: (1997^k)-1 chia het cho 10^4
3. tong cac chu so cua 1 so chinh phuong co the bang 1995 dc k?
4. tong cua 1995 stn khac 0 dung bang 1995. Hoi UCLN cua chung la bao nhieu?
Cho cac so nguyen a,b,c,d thoa man : a + b = c + d và a^2 + b^2 = c^2 + d^2. CMR : a^2014 + b^2014 = c^2014 d^2014
Cho cac so nguyen a,b,c,d thoa man : a + b = c + d và a^2 + b^2 = c^2 + d^2. CMR : a^2014 + b^2014 = c^2014 d^2014
tim cac so nguyen duong a,b,c thoa man a+b+c=91 va b^2=a*c
bai 1 tim so tu nhien co 4 chu so ab cd biet abcd+abc+ab+a=4321.tim abcd
bai 2 cho m , n la cac so tu nhien va p la so nguyen to thoa man 9/m-1=m+n/p. tinh A= p^2-n
bai 3 tim so co 3 chu so biet abc 1000/a+b+c=abc.
tim cac so nguyen a,b,c thoa man dong thoi 3 dang thuc
a*b*c+a=1333;a*b*c+b=1335;a*b*c+c=1341