Bài `2:`

`a) 1,15 - (-3/10) + 1 3/4`

`= 23/20 + 3/10 + 7/4`

`= 23/20 + 6/20 + 35/20`

`= (23+6+35)/20`

`= 64/20 = 16/5`

`b) (6/11 + 3 4/9) * 4/5 - 4/5 * (4/9 + 39/11)`

`= 4/5 * (6/11 + 3 4/9 - 4/9 - 39/11)`

`= 4/5 * (6/11 - 39/11 + 31/9-4/9)`

`= 4/5 * (-3+3)`

`= 4/5 * 0`

`= 0`

`c) (-5)/8 + 1,8 - 2 5/7 - 3/8 - 4/5 + 12/7`

`= (-5)/8 + 9/5 - 19/7 - 3/8 - 4/5 + 12/7`

`= ((-5)/8 - 3/8) + (9/5-4/5) + (-19/7 + 12/7)`

`= (-1) + 1 - 1`

`= -1`

`d) 2024.(3/5-2 6/13 + 0,25) - 2024.(-3 3/4 + 7/13 + 3/5)`

`= 2024.(3/5-32/13 + 1/4+15/4 - 7/13 - 3/5)`

`= 2024.(3/5-3/5-32/13-7/13+1/4+15/4)`

`= 2024.(-3+4)`

`= 2024.1`

`= 2024`