Hộ vs ak là một loài thực vật có hoa trong họ cúc ơi chị có đi

Bài 3:

`a)` `21/47 + 9/45 + 26/47 + 4/5`

`= (21/47 + 26/47) + (9/45 + 4/5)`

`= 47/47 + (1/5 + 4/5)`

`= 1 + 5/5`

`= 1 + 1 = 2`

`b)` `15/12 + 5/13 - 3/12 - 18/13`

`= (15/12 - 3/12) + (5/13 - 18/13)`

`= 12/12 - 13/13`

`= 1 - 1 = 0`

`c)` `5/34 + 7/21 + 29/34 - 1 15/17 + 2/3`

`= (5/34 + 29/34) + (7/21 + 2/3) - 32/17`

`= 34/34 + (1/3 + 2/3) - 32/17`

`= 1 + 1 - 32/17`

`= 2 - 32/17  = 2/17`

`d)` `7/6 * 3 1/4 + 7/6 * (-0,25)`

`= 7/6 * (3 1/4 - 0,25)`

`= 7/6 * (13/4 - 1/4)`

`= 7/6 * 12/4`

`= 7/6 * 3 = 7/2`

`e)` `1/7 * 1/3 + 1/7 * 1/2 - 1/7`

`= 1/7 * (1/3 + 1/2 - 1)`

`= 1/7 * (2/6 + 3/6 - 6/6)`

`= 1/7 * (-1/6) = -1/42`

`f)` `5/15 + 14/25 - 12/9 + 2/7 + 11/25`

`= 1/3 + 14/25 - 4/3 + 2/7 + 11/25`

`= (1/3 - 4/3) + (14/25 + 11/25) + 2/7`

`= -3/3 + 25/25 + 2/7`

`= -1 + 1 + 2/7 = 2/7`

`g)` `5/8 * 17 1/3 - 41 1/3 * 5/8 + 21`

`= 5/8 * (17 1/3 - 41 1/3) + 21`

`= 5/8 * (52/3 - 124/3) + 21`

`= 5/8 * (-24) + 21`

`= -15 + 21 = 6`

`h) -(9/5 + 16/3) + (-2024 + 9/5) - 2/3`
`= -9/5 - 16/3 - 2024 + 9/5 - 2/3`
`= (-9/5 + 9/5) + (-16/3 - 2/3) - 2024`
`= 0 - 18/3 - 2024`
`= -6 - 2024 = -2030`