Ответ:

8 8/11-z= 3 9/11.  z=8 8/11- 3 9/11.   z=5 8/11-9/11. z= 4 10/11

а-4 3/5= 2 4/5,  а=4 3/5+ 2 4/5, а= 6 7/5, а=7 2/5

8 16/27- (х-2 17/27)= 8 5/27, 8 16/27-х+2 17/27=8 5/27, 10 33/27-х=8 5/27,      11 6/27-х=8 5/27, х= 11 6/27-8 5/27, х=3 1/27