K = 4/2 - 4/4 + 4/4 - 4/6 + ....... + 4/2008 - 4/2010
K = 4/2 - 4/2010
K = 4016/2010 = 1/1003/1005
\(K=2\left(\frac{2}{2.4}+\frac{2}{4.6}+...+\frac{2}{2008.2010}\right)\)
\(K=2\left(\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+...+\frac{1}{2002}-\frac{1}{2010}\right)\)
\(K=2\left(\frac{1}{2}-\frac{1}{2010}\right)\)
\(K=2.\frac{502}{1005}\)
\(K=\frac{1004}{1005}\)
Bạn Nguyễn Thanh Bình làm đúng rồi
K =4/2-4/4+4/4-4/6+.....+4/2008-4/2010
K =4/2-4/2010
K =4016/2010=1/1003/1005