Cho:
B=1.2.3.4.......2012.(1+1/2+1/3+1/4+.......+1/2012)
Chung minh B chia het cho 2013
cho B=1.2.3.4.....2012.(1+1\2+1\3+...+1\2012.CMR B chia hết cho 2013
cho A= 1.2.3.4..........2012.(1+1/2+1/3+1/4+............+1/2012)
Chứng minh A chia hết cho 2013
tinh B=(1.2.3.4...2012).(1+1/2+1/3+...+1/2012)
bai 1
cho 2 so nguyen a,b ko chia het cho 3 nhung khi chia cho 3 thi co cung so du chung minh ab-1 la boi cua 3 ( goi y ap dung cong thuc (a+b).(c+d)=a.(c+d)+b.(c+d) )
bai 2 thuc hien phep tinh M=1+2+22+23+.....+22012/22014-2
b, cho S=5+52+53+54+55+56+.........+52012 chung to S chia het cho 65
giup minh voi can ban oi!!!!!!!!!!!!!!!
cho A=1+3+32+33+.....+32011+32012 chung minh rang A-1 chia het cho 40
tim x biet |2x - 1|<5
cho B= 1.2.3...2012[1+1/2+1/3+...+1/2012]
CMR B chia het cho 2013
1.tinh
C=(1+1/1.3)(1+1/2.4)(1+1/3.5)...(1+1/2014.2016)
2.
a, so 2^100 viet trong he thap phan co bao nhieu chu so
b,Chung to rang neu p la so nguyen to lon hon 3 thi p^2 -1 chia het cho 3
3.
a,tim cac chu so a,b,c khac 0 thoa man
abbc=ab.ac.7
b,cho A=1/2.(7^2012^2014-3^92^94). chung minh A la so tu nhien chia het cho 5.
4.
a,chung minh rang ,neu
(ab+cd+eg) chia het cho 11 thi abcdeg chia het cho 11
b,chung minh rang
10^28+8 chia het cho 72
Cac ban nho ai nhanh mink tick nhung phai co du cach lam va loi giai !!!!!!!!!!!!!!!!!!!!!!!!!