Question

[Dương Thị Quỳnh]

Tính bằng cách thuận tiện nhất :

( 1 - 1 / 2 ) x ( 1 - 1 / 3 ) x ( 1 - 1 / 4 ) x ( 1 - 1 / 5 )

Answer 1

[Kiệt Nguyễn]

\(\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)\left(1-\frac{1}{5}\right)\)

\(=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}.\frac{4}{5}\)

\(=\frac{1.2.3.4}{2.3.4.5}\)

\(=\frac{1}{5}\)