Tính tổng:
\(S=2015+\frac{2015}{1+2}+\frac{2015}{1+2+3}+....+\frac{2015}{1+2+3+...+2016}\)
Tính tổng: S= 2016+\(\frac{2016}{1+2}+\frac{2016}{1+2+3}+...+\frac{2016}{1+2+3+...+2015}\)
giúp mình nha
Tinh:
S=2015+\(\frac{2015}{1+2}\)+\(\frac{2015}{1+2+3}\)+\(\frac{2015}{1+2+3+4}\)+...+\(\frac{2015}{1+2+3+...+2016}\)
Tinh:
S=2015+\(\frac{2015}{1+2}\)+\(\frac{2015}{1+2+3}\)+...+\(\frac{2015}{1+2+3+...+2016}\)
\(A=\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2015}+\frac{1}{2016}}{\frac{2015}{1}+\frac{2014}{2}+\frac{2013}{3}+...+\frac{1}{2014}+\frac{1}{2015}}\)
Tính S :
\(S=\frac{1}{2}\left(1+2\right)+\frac{1}{3}\left(1+2+3\right)\) \(+...+\frac{1}{2015}\left(1+2+...+2014+2015\right)\) \(+\frac{1}{2016}\left(1+2+...+2015+2016\right)\)
Tính S :
\(S=\frac{1}{2}\left(1+2\right)+\frac{1}{3}\left(1+2+3\right)\) \(+...+\frac{1}{2015}\left(1+2+...+2014+2015\right)\) \(+\frac{1}{2016}\left(1+2+...+2015+2016\right)\)
Tính: \(A=\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2016}}{\frac{2015}{1}+\frac{2014}{2}+...+\frac{1}{2015}}\)