Question

Tính nhanh a) 5x4+9x5-5x3-10. b)4x7+4x6-4x3-4

Answer 1

a, 5 x 4 + 9 x 5 - 5 x 3  - 10

= 5 x ( 4 + 9 - 3) - 10

= 5 x ( 13 - 3) - 10

= 5 x 10 - 10

= 40 

b, 4 x 7 + 4 x 6 - 4 x 3 - 4

= 4 x 7 + 4 x 6 - 4 x 3 - 4 x1

= 4 x ( 7 + 6 - 3 -1)

= 4 x 9

= 36

 

 

Answer 2

`5xx4+9xx5-5xx3-10`

`= 5 xx (4+9-3 -10)`

`= 5 xx 0`

`=0`

`-----`

`4 xx7 + 4 xx6 - 4xx3-4`

`=4 xx7 + 4 xx6 - 4xx3-4 xx 1`

`=  4xx (7+6-3-1)`

`= 4 xx 9`

`=36`

Answer 3

5.4 + 9.5 - 5.3 - 10

=5.4 + 9.5 - 5.3 - 5.2

=5.(4 + 9 - 3 - 2 )

=5. 8

= 40

b, 4 . 7 + 4 . 6 - 4 . 3 - 4

=4. ( 7 + 6 - 3 - 1 )

= 4. 9

= 36