CM 1-1/2-1/22-....-1/22014>1/2015
Cho S = 1 - 2 + 22 -23 +...+22012 - 22013 . Tính 3S - 22014
\(S=1-2+2^2-2^3+...+2^{2012}-2^{2013}\)
\(\Rightarrow2S=2-2^2+2^3-2^4+...+2^{2013}-2^{2014}\)
\(\Rightarrow2S+S=2-2^2+2^3-...-2^{2014}+1-2^2-2^3+...-2^{2013}\)
\(\Rightarrow3S=1-2^{2014}\)\(\Rightarrow3S-2^{2014}=1-2^{2015}\)
Tìm số dư trong phép chia 2 2014 cho
1 + 2 + 2 2 + 2 3 + . . . + 2 2011
b) Tìm số dư trong phép chia 2 2014 cho 1 + 2 + 2 2 + 2 3 + . . . + 2 2011
xam xi
M = 1 + 22 + 23 + ... + 22012 / 22014 - 2
Tính M
Đặt N = 1 + 2 + 22 +...+ 22012
2N = 2 + 22 + 23 +...+ 22013
2N - N = (2 + 22 + 23+....+ 22013) - (1 + 2 + 22 +....+ 22012)
N = 22013 - 1
Thay N vào M ta được:
\(M=\dfrac{2^{2013}-1}{2^{2014}-2}=\dfrac{2^{2013}-1}{2\left(2^{2013}-1\right)}=\dfrac{1}{2}\)Đặt \(N=1+2+2^2+...+2^{2012}\)
\(2N=2+2^2+2^3+...+2^{2013}\)
\(2N-N=\left(2+2^2+2^3+...+2^{2013}\right)-\left(1+2+2^2+...+2^{2012}\right)\)
\(N=2^{2013}-1\)
Thay N vào M ta được:
\(M=\dfrac{2^{2013-1}}{2^{2014}-2}=\dfrac{2^{2013}-1}{2\left(2^{2013}-1\right)}=\dfrac{1}{2}\)
Tham khảo link: https://olm.vn/hoi-dap/detail/80564627052.html
M = 1 + 22 + 23 + ... + 22012 / 22014 - 2
Tính M
Cho S=1-2+2^2-2^3+2^4-2^5+...+2^{2013}-2^{2014}.S=1−2+22−23+24−25+...+22013−22014. Khi đó 1-3S=2^x.1−3S=2x.
Vậy x=...............................
ta có: \(S=1-2+2^2-2^3+2^4-2^5+...+2^{2013}-2^{2014}\)
\(\Rightarrow2S=2-2^2+2^3-2^4+2^5-2^6+...+2^{2014}-2^{2015}\)
=> 2S + S = -22015 + 1
=> 3S = -22015 + 1
=> 3S - 1 = -22015
=> 1 - 3S = 22015
( cn về S = 1 - 2 + 22 - 23 + 24-25+...+22013 - 22014 mk vx chưa hiểu quy luật của nó lắm, thật lòng xl bn nha! mk chỉ bk z thoy!)
(1/2+2015/2016+2016/2017+1)(2015/2016+2016/2017+7/22)-(1/2+2015/2016+2016/2017)(2015/2016+2016/2017+7/22+1)
(1/2+2015/2016+216/2017+1)(2015/2016+2016/2017+7/22)-(1/2+2015+2016)(2015/2016+2016/2017+7/22+1)
Tính
(1/2 + 2015/2016 + 2016/2017 + 1)(2015/2016 + 2016/2017 + 7/22) - (1/2 + 2015/2016 + 2016/2017)(2015/2016 + 2016/2017 + 7/22 + 1)
Giúp mk với
(1/2+2015/2016+2016/2017+1)(2015/2016+2016/2017+7/22)-(1/2+2015/2016+2016/2017)(2015/2016+2016/2017+7/22+1)