Question

Tính thuận tiện

2, \(\dfrac{5}{7}.\dfrac{5}{11}+\dfrac{5}{7}.\dfrac{2}{11}-\dfrac{5}{7}\)

Answer 1

`2, 5/7 xx 5/11 + 5/7 xx 2/11 - 5/7`

`= 5/7 xx (5/11 + 2/11 - 1)`

`= 5/7 xx -4/11`

`= -20/77`

Answer 2

`5/7 . 5/11 + 5/7 . 2/11 - 5/7`

`=5/7 . 5/11 + 5/7 . 2/11 - 5/7 . 1`

`=5/7 . (5/11 + 2/11 - 1)`

`=5/7 . (5/11 +2/11-11/11)`

`=5/7 . ((5+2-11)/11)`

`=5/7. (-4)/11`

`=(-20)/77`

Answer 3

`2) 5/7 . 5/11 + 5/7 . 2/11 - 5/7`

`= 5/7 . (5/11+2/11-1)`

`=5/7 . (-4)/11`

`=(-20)/11`