1) (2 9/56-а)-16/59=1 5/59
2 9/59 - а - 16/59= 1 5/59
-а=1 5/59+16/59-2 9/59
-а=1 21/59 - 2 9/59
-а= -(2 9/59 - 1 21/59)
-а=-(1 68/59-1 21/59)
а=47/59
2) 3 4/9-(х-1 7/9)=2 2/9
3 4/9-х+1 7/9= 2 2/9
-х=2 2/9-1 7/9 - 3 4/9
-х= 1 11/9 - 1 7/9 - 3 4/9
-х=4/9-3 4/9
-х= -(3 4/9-4/9)
-х=-3
х=3
3) 10 6/10 -(7 3/10-у)=4 9/10
10 6/10-7 3/10-у=4 9/10
3 3/10-у=4 9/10
-у= 4 9/10 - 3 3/10
у= - 1 6/10= - 1 3/5
4) 17 18/35 - (n+ 4 23/35)=9 12/35
17 18/35-n - 4 23/35=9 12/35
-n=9 12/35+4 23/35-17 18/35
-n=13 35/35-17 18/35
-n=14-17 18/35
-n=-3
n=3