Question

\((\frac{1}{2}-1)\times(\frac{1}{3}-1)...\times(\frac{1}{2009}-1)\)

Answer 1

= 1/2*2/3*3/4*4/5*...*2008/2009

= 1/2009 (triệt tiêu)

Answer 2

(\(\frac{1}{2}\)-1)\(\times\left(\frac{1}{3}-1\right)\)...\(\times\)\(\times\left(\frac{1}{2009}-1\right)\)

=\(-\frac{1}{2}\times-\frac{2}{3}\times...\times-\frac{2008}{2009}\)

=\(-1\times-\frac{2008}{2009}\)

=\(\frac{2008}{2009}\)