A=1/2+1/2^2+1/2^3+...+1/2^2016 (1)
2A=1+1/2+1/2^2+...+1/2^2015 (2)
Lấy (2)-(1) được:
A=1+1/2+1/2^2+...+1/2^2015-(1/2+1/2^2+1/2^3+...+1/2^2016)
A=1+1/2+1/2^2+...+1/2^2015-1/2-1/2^2-1/2^3-...-1/2^2016
A=1-1/2^2016
Vậy A=1-1/2^2016
A=1/2+1/2^2+1/2^3+...+1/2^2016 (1)
2A=1+1/2+1/2^2+...+1/2^2015 (2)
Lấy (2)-(1) được:
A=1+1/2+1/2^2+...+1/2^2015-(1/2+1/2^2+1/2^3+...+1/2^2016)
A=1+1/2+1/2^2+...+1/2^2015-1/2-1/2^2-1/2^3-...-1/2^2016
A=1-1/2^2016
Vậy A=1-1/2^2016
Tính tổng sau:
A=\(\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+..............+\frac{1}{2^{2015}}+\frac{1}{2^{2016}}\)
Tính tổng sau:A=\(\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{2015}}+\frac{1}{2^{2016}}\)
Tính tổng S = \(2015+\frac{2015}{1+2}+\frac{2015}{1+2+3}+...+\frac{2015}{1+2+3+...+2016}\)
Tính tổng:
\(S=2015+\frac{2015}{1+2}+\frac{2015}{1+2+3}+....+\frac{2015}{1+2+3+...+2016}\)
Tính tổng sau: A = \(\frac{1}{2}\)+ \(\frac{1}{2^2}\) + \(\frac{1}{2^3}\)+ ... + \(\frac{1}{2^{2015}}\)+ \(\frac{1}{2^{2016}}\)
Tính tổng: S= 2016+\(\frac{2016}{1+2}+\frac{2016}{1+2+3}+...+\frac{2016}{1+2+3+...+2015}\)
giúp mình nha
Tính tổng
\(A=\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+...+\frac{1}{100}\)
\(B=\frac{2}{3}+\frac{3}{4}+\frac{4}{5}+...+\frac{2015}{2016}\)
Tính: \(A=\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2016}}{\frac{2015}{1}+\frac{2014}{2}+...+\frac{1}{2015}}\)
Tính: \(A=\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2016}}{\frac{2015}{1}+\frac{2014}{2}+...+\frac{1}{2015}}\)