Tính nhanh:
a, - \(\frac{2}{3}\)- 2015. 2016 + \(\frac{1}{2}\)- 2015. (-2017) - \(\frac{-1}{6}\)
b, \(\frac{-11}{13}\)- \((\frac{23}{-25}-\frac{-2011}{2017})\)\(+\frac{-11}{2017}\)
c, \(\frac{2}{1.3}+\frac{2}{3.5}+\frac{2}{5.7}+...+\frac{2}{201.203}\)
d, \(\frac{-4}{2.5}-\frac{4}{5.8}-\frac{4}{8.11}-...-\frac{4}{2015.2018}\)
Câu a,b bạn bấm máy tính là ra ngay
c) 2/1.3+2/3.5+2/5.7+...+2/201.203
=1-1/3+1/3-1/5+1/5-1/7+...+1/201-1/203
=1-1/203
=202/203
nha, hok tốt