(1 - 1/2)(1 - 1/3)(1 - 1/4) ... (1 - 1/99)
= 1/2*2/3*3/4*...*98/99
= 1/99
Ta có : (1 -1/2)(1-1/3)(1-1/4)..(1-1/99)
=1/2 .2/3.3/4....98/99
=1/99
\(\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{99}\right)\)
\(=\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot.....\cdot\frac{98}{99}\)
\(=\frac{1\cdot2\cdot3.....98}{2\cdot3\cdot4.....99}=\frac{1}{99}\)
