Question

Tinh 

            \(\left(1-\frac{1}{1+2}\right).\left(1-\frac{1}{1+2+3}\right)....\left(1-\frac{1}{1+2+3+,....+2016}\right)\) 

Answer 1

(1 - 1/1+2).(1 - 1/1+2+3)...(1 - 1/1+2+3+...+2016)

= 2/(1+2)×2:2 . 5/(1+3)×3:2 ... (1+2016)×2016:2-1/(1+2016).2016:2

= 4/2×3 . 10/3×4 ... (2017.1008-1).2/2016.2017

= 1×4/2×3 . 2×5/3×4 ... 2015×2018/2016×2017

= 1×2×...×2015/2×3×...×2016 . 4×5×...×2018/3×4×...×2017

= 1/2016 . 2018/3

= 1009/3024

Answer 2

1 nha bạn 

nhớ k cho mình nha 

:)

mình nói đùa thôi không phải 1 đâu :V