Question

1+\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+...\frac{1}{300}\)

Answer 1

Tính tổng hả bn

Answer 2

bn ơi đề bài là gì vậy

Answer 3

\(A=1+\frac{1}{3}+\frac{1}{6}+...+\frac{1}{300}\)

\(=2\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+...+\frac{1}{600}\right)\)

\(=2\left(\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}+...+\frac{1}{24\times25}\right)\)

\(=2\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{24}-\frac{1}{25}\right)\)

\(=2\left(1-\frac{1}{25}\right)=2\times\frac{24}{25}=\frac{48}{25}\)

Answer 4

tính j tke bn 

ko ghi đề bài ko lm đc !