tính: D=(1+1/3+1/5+...+1/2017)-(1/2+1/4+1/6+...+1/2018)/1/1010+1/1011+1/1012+...+1/2018
Những câu hỏi liên quan
Tính:
E=(1+1/3+1/5+...+1/2017)-(1/2+1/4+1/6+...+1/2018) / 1/1010+1/1011+1/1012+...+1/2018
Cho A=1-1/2+1/3-1/4+........+1/2017-1/2018 và
B=1/1010+1/1011+1/1012+.......+1/2017+1/2018
Tính A/B^2018
ta có: \(A=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{2017}-\frac{1}{2018}\)
\(A=\left(1+\frac{1}{3}+...+\frac{1}{2017}\right)-\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2018}\right)\)
\(A=\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2018}\right)-2.\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2018}\right)\)
\(A=\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2018}\right)-\left(1+\frac{1}{2}+...+\frac{1}{1009}\right)\)
\(A=\frac{1}{1010}+\frac{1}{1011}+\frac{1}{1012}+...+\frac{1}{2017}+\frac{1}{2018}\)
\(\Rightarrow A=B\left(=\frac{1}{1010}+\frac{1}{1011}+\frac{1}{1012}+...+\frac{1}{2017}+\frac{1}{2018}\right)\)
\(\Rightarrow\frac{A}{B^{2018}}=\frac{A}{A.B^{2017}}=\frac{1}{B^{2017}}\)
=> \(\frac{A}{B^{2018}}=\frac{1}{\left(\frac{1}{1010}+\frac{1}{1011}+\frac{1}{1012}+...+\frac{1}{2017}+\frac{1}{2018}\right)^{2017}}\)
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Cho A = 1 - 1/2 + 1/3 + 1/4 + .... + 1/2017 +1/2018 + 1/2019
B = 1/1010 + 1/1011 + 1/1012 + .... + 1/2017 + 1/2018 + 1/2019
Tính (A-B-1)2019
D=(1+1/3+1/5+...+1/2017)-(1/2+1/4+1/6+...+1/2018)/1/1010+1/1011+...+1/2018
giúp mình lun nha mình đang cần gấp...mình k cho
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Cho A = 1 - 1/2 + 1/3 + 1/4 + .... + 1/2017 +1/2018 + 1/2019
B = 1/1010 + 1/1011 + 1/1012 + .... + 1/2017 + 1/2018 + 1/2019
Tính (A-B-1)2019
Tính \(\frac{\left(1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{2017}\right)}{\frac{1}{1010}+\frac{1}{1011}+\frac{1}{1012}+...+\frac{1}{2018}}\)
sory mk ghi sai đề \(\frac{\left(1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{2017}\right)-\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{2018}\right)}{\frac{1}{1010}+\frac{1}{1011}+\frac{1}{1012}+...+\frac{1}{2018}}\)
Đặt \(T=\left(1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{2017}\right)-\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{2018}\right)\)
\(=\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2017}+\frac{1}{2018}\right)-2\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{2018}\right)\)
\(=\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2018}\right)-\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{1009}\right)\)
\(=\frac{1}{1010}+\frac{1}{1011}+\frac{1}{1012}+...+\frac{1}{2018}\)
Ta thấy tử số bằng với mẫu số nên phân số có giá trị bằng 1.
A=1-\(\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{2017}-\dfrac{1}{2018}+\dfrac{1}{2019}\)
B=\(\dfrac{1}{1010}+\dfrac{1}{1011}+\dfrac{1}{1012}+...+\dfrac{1}{2019}\)
Tính \(^{\left(A-B\right)^{2019}}\)
Chứng minh rằng 1 - 1/2 + 1/3 - 1/4 + 1/5 - ... - 1/2018 = 1/1010 + 1/1011 + 1/1012 + ... + 1/2018
cho S =1-1/2+1/3-1/4+...+1/2017-1/2018+1/2019
Va P=1/1010+1/1011+1/1012+...+1/2019
Tinh (S-P)2018
LM GIÚP MÌNH VỚI
CM ƠN TRƯỚC NHA
Ta có : S =\(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{2017}-\frac{1}{2018}+\frac{1}{2019}\)
\(\Rightarrow S=1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2017}+\frac{1}{2018}+\frac{1}{2019}\)\(-2\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2018}\right)\)
\(\Rightarrow S=1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2019}\)\(-\left(1+\frac{1}{2}+...+\frac{1}{1009}\right)\)
\(\Rightarrow S=\frac{1}{1010}+\frac{1}{1011}+...+\frac{1}{2019}\)
\(\Rightarrow S=P\)
Khi đó : \(\left(S-P\right)^{2018}=0^{2018}=0\)
k chi mik nha!
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A=1+1/2+1/3+1/4+...+1/2^2018-1 Chứng tỏ A<2018