Question

tính nhanh 555x999

Answer 1

\(555\cdot999\\ =555\cdot\left(1000-1\right)\\ =555\cdot1000-555\\ =555000-555\\ =554445\)

Answer 2

`555 . 999`

`= 555 . (1000 - 1)`

`= 555 . 1000 - 555.1`

`= 555000 - 555`

`= 554445`

Answer 3

555 . 999

= 555 . (1000 - 1)

= 555 . 1000 - 555

= 555000 - 555

= 554445