9.2^x.(2^1005-2^1002+.....+2^3-1)=2^1008-1 *
A=2^1005-2^1002+...+2^3-1 2^3 .
A=2^2.(2^1005-2^1002+......+2^3-1) 8.
A=2^1008-2^1005+.....+2^6-2^3
A=2^1005-2^1002+.....+2^3-1 8.A+A=2^1008-1 9.
A=2^1008-1
Thay 9.a=2^1008-1 vào * ta có: 2^x.(2^1008-1)=2^1008-1
2^x=(2^1008-1):(2^1008-1)
2^x=1
2^x=2^0
x=0
vậy x=0
Lập đề bài cho bài toán này
B=1/1008 * 2004+1/1009*2004+...+1/2014*1008
cho
A=1/1008+1/1009+.....+1/2014
B=1/1008*2014+1/1009*2013+......+1/2014*1008
hay chung minh rang B/A la so nguyen
Tính B=1/1008*2014 + 1/1009*2013 + 1/1010*2012 + ...+ 1/2014*1008
Tính tổng 1/1008 + 1/1009 + 1/1010+...+ 1/2016
Ta có :a=1/2+1/4+1/6+...+1/1008.Tính A
chứng minh: 1/1008x2014+1/1009x2013+....+1/2014x1008=1/1511x(1/1008+1/1009+...+1/2014)
CMR :1/1.2+1/3.4+...+1/2013.2014=1/1008+1/1009 +........+1/2013+1/2014
chứng minh: 1- 1/2+ 1/3-...- 1/2012= 1/1007+ 1/1008+... + 1/2012 ~~giúp mk nhé