\(tinh;\frac{1}{51\cdot100}+\frac{1}{52\cdot99}+...+\frac{1}{99\cdot52}+\frac{1}{100\cdot51}\)

\(choA=\frac{1}{1\cdot2}+\frac{1}{3\cdot4}+\frac{1}{5\cdot6}+...+\frac{1}{99\cdot100};B=\frac{1}{51\cdot100}+\frac{1}{52\cdot99}+...+\frac{1}{52\cdot99}+\frac{1}{100\cdot51}\)

Giải phương trình

\(\left(\frac{1}{1\cdot51}+\frac{1}{2\cdot52}+\frac{1}{3\cdot53}+\cdot\cdot\cdot+\frac{1}{10\cdot60}\right)x=\frac{1}{1\cdot11}+\frac{1}{2\cdot12}+\cdot\cdot\cdot+\frac{1}{50\cdot60}\)

Giải phương trình

\(\left(\frac{1}{1\cdot51}+\frac{1}{2\cdot52}+\frac{1}{3\cdot53}+\cdot\cdot\cdot+\frac{1}{10\cdot60}\right)\cdot x=\frac{1}{1\cdot11}+\frac{1}{2\cdot12}+\cdot\cdot\cdot+\frac{1}{50\cdot60}\)

Tính  \(\frac{1\cdot3\cdot5\cdot7\cdot9...99}{50\cdot51\cdot52...100}\)

Tính          

\(\frac{1\cdot3\cdot5\cdot7...99}{50\cdot51\cdot52...100}\)

Tính:\(\left(\frac{1}{51}+\frac{1}{52}+\frac{1}{53}+\frac{1}{54}+...+\frac{1}{100}\right):\left(\frac{1}{1\cdot2}+\frac{1}{3\cdot4}+\frac{1}{5\cdot6}+...+\frac{1}{99\cdot100}\right)\) 

Cho \(A=\frac{1}{1\cdot2}+\frac{1}{3\cdot4}+\frac{1}{5\cdot6}+....+\frac{1}{99\cdot100}\)

\(B=\frac{1}{50}+\frac{1}{51}+\frac{1}{52}+.....+\frac{1}{100}\)

Khi đó A-b=????

Cho A=\(\frac{1}{1\cdot2}+\frac{1}{3\cdot4}+\frac{1}{5\cdot6}+........+\frac{1}{99\cdot100}\)và B=\(\frac{1}{50}+\frac{1}{51}+\frac{1}{52}+.......+\frac{1}{100}\)khi đó A-B =.......? ai giải thích hộ mk vs nhá. thanks