S-1+2+3-4-5+6+7+8-9-10+11+12+13-14-15+...+2011+2012+2013-2014-2015
(Tính)
S-1+2+3-4-5+6+7+8-9-10+11+12+13-14-15+...+2011+2012+2013-2014-2015
(Đề bài tính)
S-1+2+3-4-5+6+7+8-9-10+11+12+13-14-15+...+2011+2012+2013-2014-2015
(Đề bài tính)
Tính tổng: \(\frac{1}{5\cdot6}+\frac{1}{10\cdot9}+\frac{1}{15\cdot12}+.......+\frac{1}{3350\cdot2013}\)
tính tổng:\(ys=\frac{1}{5\times6}+\frac{1}{10\times9}+\frac{1}{15\times12}+............+\frac{1}{3350\times2013}\)
Tính tổng:
\(S=\frac{1}{5\times6}+\frac{1}{10\times9}+\frac{1}{15\times12}+...+\frac{1}{3350\times2013}\)
\(S=\frac{1}{5\times6}+\frac{1}{10\times9}+\frac{1}{15\times12}+...+\frac{1}{3350\times2013}\)
Tính A=-1-2+3+4-5-6+7+8-9-10+11+12-.......-2013-2014+2015+2016
Tính A = ( -1 ) -2+3+4 -5-6+7=8-9-10+11+12 - ....-2013 - 2014+2015+2016