Ta có : \(\left(1-\frac{1}{99}\right)\text{ x }\left(1-\frac{1}{100}\right)\text{ x }.....\text{ x }\left(1-\frac{1}{2006}\right)\)

\(=\frac{98}{99}\text{ x }\frac{99}{100}\text{ x }\frac{100}{101}\text{ x }......\text{ x }\frac{2005}{2006}\)

\(=\frac{98\text{ x }99\text{ x }100\text{ x }......\text{ x }2005}{99\text{ x }100\text{ x }101\text{ x }......\text{ x }2006}\)

\(=\frac{98}{2006}=\frac{49}{1003}\)

(1-1/99).(1-1/100)....(1-1/2006) =(99/99-1/99).(100/100-1/100)....(2006/2006-1/2006) = (98/99).(99/100)...(2005/2006) =98/2006=..

1-1/99).(1-1/100)....(1-1/2006)
=(99/99-1/99).(100/100-1/100)....(2006/2006-1/2006) = (98/99).(99/100)...(2005/2006) =98/2006=..

Tinh bang cach thuan tien nha mn

\(\left(1-\frac{1}{99}\right)\times\left(1-\frac{1}{100}\right)\times...\times\left(1-\frac{1}{2006}\right)\)

\(=\left(\frac{99}{99}-\frac{1}{99}\right)\times\left(\frac{100}{100}-\frac{1}{100}\right)\times\left(\frac{2006}{2006}-\frac{1}{2006}\right)\)

\(=\frac{98}{99}\times\frac{99}{100}\times...\times\frac{2005}{2006}\)

\(=\frac{98\times99\times...\times2005}{99\times100\times...\times2006}\)

\(=\frac{98}{2006}=\frac{49}{1003}\)

= 49\1003 đung ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss