`f)` `4/9:(-1/7)+6 5/9:(-1/7)`

`=4/9. (-7/1)+59/9. (-7/1)`

`=(-7). (4/9+59/9)`

`=(-7). 63/9`

`=(-7). 7`

`=-49`

``

`g)``(-1)/4. 13 9/11-0,25. 6 2/11`

`=(-1)/4. 152/11-1/4. 68/11`

`=(-1)/4. 152/11+(-1)/4. 68/11`

`=(-1)/4. (152/11+68/11)`

`=(-1)/4. 220/11`

`=(-1)/4. 20`

`=(-20)/4`

`=-5`

``

`h)` `5 27/5+27/23+0,5-5/27+16/23`

`=52/5+27/23+1/2-5/27+16/23`

`=(27/23+16/23)+(52/5+1/2)-5/27`

`=43/23+109/10-5/27`

`=2937/230-5/27`

`=79299/6210-1150/6210`

`=78149/6210`

``

`i)` `3/8. 27 1/5-51 1/5. 3/8+19`

`=3/8. 136/5-256/5. 3/8+19`

`=3/8. (136/5-256/5)+19`

`=3/8. (-24)+19`

`=-9+19`

`=10`