làm nhanh giúp mình nha trừ câu a

Đáp án:

`b, 5/18 - 1,456 : 7/25 + 4,5 . 4/5`

`= 5/18 - 26/5 + 18/5`

`= -443/90 + 18/5`

`= -119/90`.

$\\$

`c, 0,5 . \sqrt{400} - \sqrt{1/16}`

`= 0,5 . 20 - 1/4`

`= 10 - 1/4`

`= 39/4`.

$\\$

`d, ( \sqrt{6,25} - 5.\sqrt{0,49} ) (19 . \sqrt{36/361} - 17.  \sqrt{81/289} )`

`= (5/2 - 5.7/10 ) (19 . 6/19 - 17. 9/17 )`

`= (5/2 - 7/2) (6 - 9)`

`= (-1) . (-3)`

`= 3`.