4/9.13/3-23/3-4/3.10/9

5,36.12,34+(-5,36).2,34

`a, 9/11 - 7/8 + 13/11 + (-1)/8`

`= ( 9/11 + 13/11 ) + (-7/8 - 1/8 )`

`= 22/11 + (-8)/8`

`= 2 + (-1)`

`= 1`

`c, 19/24 - 49/25 + 5/24 - 51/25`

`= ( 19/24 + 5/24 ) + ( -49/25 - 51/25 )`

`= 24/24 + (-100)/25`

`= 1 + (-4)`

`=-3`

`b, 4/9 . 13/3 - 23/3 - 4/3 . 10/9`

`= 4/9 . 13/3 - 23/3 - 10/3 . 4/9`

`= 4/9 . ( 13/3 - 10/3 ) - 23/3`

`= 4/9 . 3/3 - 23/3`

`= 4/9 . 1 - 23/3`

`= 4/9 - 23/3`

`= -65/9`

`d, 5,36 . 12,24 + (-5,36) . 2,34`

`= 5,36 . 12,24 + 5,36 . (-2,34 )`

`= 5,36 . [ 12,24 + (-2,34)]`

`= 5,36 . 10`

`=53,6`