Question

\(\frac{1}{2\cdot3}\)+\(\frac{1}{3\cdot4}\)+\(\frac{1}{4\cdot5}\)+\(\frac{1}{5\cdot6}\)+\(\frac{1}{6\cdot7}\)+\(\frac{1}{7\cdot8}\)+\(\frac{1}{8\cdot9}\)+ \(\frac{1}{9\cdot10}\)

Tính hộ tôi [Lưu ý : dấu chấm bằng dấu nhân]

Answer 1

bai nay de thui

nhung bay gio mk ban

luc nao ranh mk lam

cho nha

minhpham@gmail.com

Answer 2

To cu tuong day kien thuc lop 6

Answer 3

\(=\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+\frac{1}{7}-\frac{1}{8}+\frac{1}{8}-\frac{1}{9}+\frac{1}{9}-\frac{1}{10}=\frac{1}{2}-\frac{1}{10}=\frac{5-1}{10}=\frac{4}{10}=\frac{2}{5}\)

Answer 4

\(\frac{1}{2}.\frac{1}{10}=\frac{1}{20}\)

Answer 5

= 1- 1/20

= 1/ 19

Answer 6

Ta có : \(\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+.....+\frac{1}{9.10}\)

\(=\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+.....+\frac{1}{10}\)

\(=\frac{1}{2}-\frac{1}{10}=\frac{5}{10}-\frac{1}{10}=\frac{2}{5}\)

Answer 7

= 1 - 1/20 

= 2/5

Answer 8

\(=\left(\frac{1}{2}-\frac{1}{3}\right)+\left(\frac{1}{4}-\frac{1}{5}\right)+...+\left(\frac{1}{9}-\frac{1}{10}\right)\)

\(=\frac{1}{2}-\frac{1}{3}+\frac{1}{4}-\frac{1}{5}+...+\frac{1}{9}-\frac{1}{10}\)

\(=\frac{1}{2}-\left(\frac{1}{3}-\frac{1}{3}\right)-\left(\frac{1}{4}-\frac{1}{4}\right)-...-\frac{1}{10}\)

\(=\frac{1}{2}-0-0-..-\frac{1}{10}\)

\(=\frac{1}{2}-\frac{1}{10}\)

\(=\frac{5}{10}-\frac{1}{10}\)

\(=\frac{4}{10}=\frac{2}{5}\)

Answer 9

\(\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}+\frac{1}{7.8}+\frac{1}{8.9}+\frac{1}{9.10}\)

\(=1.\left(\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}-\frac{1}{6}+...+\frac{1}{9}-\frac{1}{10}\right)\)

\(=1.\left(\frac{1}{2}-\frac{1}{10}\right)\)

\(=1.\frac{2}{5}\)

\(=\frac{2}{5}\)