Question

Tính nhanh

M = \(\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}+.......+\frac{2}{97.99}\)

 

Answer 1

Ta có: \(M=\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}+......+\frac{2}{97.99}\)

         \(M=\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+......+\frac{1}{97}-\frac{1}{99}\)

         \(M=\frac{1}{3}-\frac{1}{99}\)

        \(M=\frac{32}{99}\)

Answer 2

\(M=\frac{2}{3\cdot5}+\frac{2}{5\cdot7}+\frac{2}{7\cdot9}+...+\frac{2}{97\cdot99}\)

\(M=\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+...+\frac{1}{97}-\frac{1}{99}\)

\(M=\frac{1}{3}-\frac{1}{99}\)

\(M=\frac{32}{99}\)

Answer 3

\(\frac{32}{99}\)

đúng nha Miyuki

Answer 4

\(M=\frac{32}{99}\)

ĐS \(\frac{32}{99}\)

TÍCH CHO MIK , MIK TÍCH LẠI

Answer 5

32/99 dung khong