A = 1/2 x 2/3 x.....x 2009/2010 = 1x2x3x....x2009 / 2x3x4x.........x 2010
A = 1/ 2010
vậy A = 1/ 2010
\(A=\frac{1}{2}\times\frac{2}{3}\times...\times\frac{2009}{2010}\)
\(A=\frac{1\times2\times...\times2009}{2\times3\times2010}\)
\(A=\frac{1}{2010}\)
A = 1/2 x 2/3 x 3/4 x...x 2009/2010
A = 1/2010 ( Rút gọn Phân số )