(-1) . (-2 ) . (-3) . ... . (-2017)
NT
Những câu hỏi liên quan
Cho biểu thức : B = 2017+2017/1+2+2017/1+2+3+2017/1+2+3+4+....+2017/1+2+3+...+2012
tính 2017+2017/(1+2)+2017/(1+2+3)+...+2017/(1+2+3+...+2016)
999 - 888 - 111 + 111 - 111 + 111 - 111
= 111 - 111 + 111 - 111 + 111 - 111
= 0 + 111 - 111 + 111 - 111
= 111 - 111 + 111 - 111
= 0 + 111 - 111
= 111 - 111
= 0
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tinh M=2017+2017/1+2+2017/1+2+3+...+2017/1+2+3+...+2016
B=2017+2017/1+2+2017/1+2+3+2017/1+2+3+4+...+2017/1+2+3+...+2016
Bạn nào làm đúng mink sẽ tick
Giúp mình nhak
Máy cái /là mình ghi phần đó bạn vì mình không biét ghi phần như thế nào
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A= ( 1/2017+ 2/2016+ 3/2015+...+ 2015/3+ 2016/2+ 2017) : ( 1/2+1/3+1/4+...+1/2017+1/2018)
K-2016=1+ (1+2)+(1+2+3)+….+(1+2+3+…+2017)/2017*1+2016*2+2015*3+…+2*2016+1*2017
tìm K
a,Cho A=\(\frac{2+2^2+2^3+...+2^{2017}}{1-2^{2017}}\)
Tinh A.
b,Cho A=\(\frac{1}{2017}+\frac{2}{2017^2}+\frac{3}{2017^3}+...+\frac{2017}{2017^{2017}}+\frac{2018}{2017^{2018}}\)
CMR: A<\(\frac{2017}{2017^2}\)
Mik dang can gap.Giup mik voi.Thanks nhiu^^
a) \(A=\frac{2+2^2+...+2^{2017}}{1-2^{2017}}\)
Đặt \(B=2+2^2+...+2^{2017}\)
\(\Rightarrow2B=2^2+2^3+...+2^{2018}\)
\(\Rightarrow2B-B=\left(2^2+2^3+...+2^{2018}\right)-\left(2+...+2^{2017}\right)\)
\(\Rightarrow B=2^{2018}-2\)
\(\Rightarrow A=\frac{2^{2018}-2}{1-2^{2017}}\)
\(\Rightarrow A=\frac{-2.\left(1-2^{2017}\right)}{1-2^{2017}}\)
\(\Rightarrow A=-2\)
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b)Đề phải là CM: \(A< \frac{2017}{2016^2}\)
\(A=\frac{1}{2017}+\frac{2}{2017^2}+...+\frac{22017}{2017^{2017}}+\frac{2018}{2017^{2018}}\)
\(\Rightarrow2017A=1+\frac{2}{2017}+...+\frac{22017}{2017^{2016}}+\frac{2018}{2017^{2017}}\)
\(\Rightarrow2017A-A=\left(1+...+\frac{2018}{2017^{2017}}\right)-\left(\frac{1}{2017}+...+\frac{2017}{2017^{2017}}+\frac{2018}{2017^{2018}}\right)\)
\(\Rightarrow2016A=1+\frac{1}{2017}+\frac{1}{2017^2}+...+\frac{1}{2017^{2017}}-\frac{2018}{2017^{2018}}\)
Đặt \(\Rightarrow S=1+\frac{1}{2017}+\frac{1}{2017^2}+...+\frac{1}{2017^{2017}}\)
\(\Rightarrow2017S=2017+1+\frac{1}{2017}+...+\frac{1}{2017^{2016}}\)
\(\Rightarrow2017S-S=\left(2017+1+...+\frac{1}{2017^{2016}}\right)-\left(1+...+\frac{1}{2017^{2017}}\right)\)
\(\Rightarrow2016S=2017-\frac{1}{2017^{2017}}< 2017\)
\(\Rightarrow2016S< 2017\)
\(\Rightarrow S< \frac{2017}{2016}\)
\(\Rightarrow2016A< \frac{2017}{2016}\)
\(\Rightarrow A< \frac{2017}{2016^2}\left(đpcm\right)\)
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1+2018+2*2017+3*2016+..........................+2016*3+2017+2+2018*1
1+(1+2)+(1+2+3)+..........................(1+2+3+...............+2017+2018
\(A=\frac{\frac{2017}{1}+\frac{2016}{2}+\frac{2015}{3}+...+\frac{1}{2017}+2017}{1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2017}}\)
cho F= 2/(2017+1)+2^2/(2017^2+1)+2^3/(2017^2^2+1)+...+2^2017/2^2^2016+1)
So sánh Fvoiws 1/1008