Question

\(a,\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot\left(1-\frac{1}{4}\right)\cdot......\left(1-\frac{1}{18}\right)\cdot\left(1-\frac{1}{19}\right)\cdot\left(1-\frac{1}{20}\right)\)

Answer 1

= \(\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot\cdot\cdot\frac{19}{20}=\frac{1}{20}\)

Answer 2

=\(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}......\frac{19}{20}\)

= đến đây bn xem trong thống kê hỏi đáp nhé

 = :))

Answer 3

\(a,\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{19}\right).\left(1-\frac{1}{20}\right)\)

\(=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}...\frac{18}{19}.\frac{19}{20}\)

\(=\frac{1.2.3....18.19}{2.3.4....19.20}\)

\(=\frac{1}{20}\)