Question

Tính thuận tiện: 7,89 x 54 - 7,89 x 52 - 7,89

Answer 1

= 7,89 x (54-52-1)

= 7,89 x 1

= 7,89

Answer 2

 7,89x54-7,89x52-7,89x1

=7,89x(54-52-1)

=7,89x1

=7,89

 

Answer 3

`7,89 × 54 - 7,89 × 52 - 7,89 × 1`

`= 7,89 × (54 - 52 - 1)`

`= 7,89 ×`1`

`= 7,89`

Answer 4

                        7,89* (54-52-1)

                                =7.89*1

                                =7,89 bạn nhó