Выполните выражение: 1/2 - 1/3 ; 3/5-4/7; 5/7-1/6; 3/+4/5; 3/3/4+2/9

1/2 - 1/3=3/6 - 2/6=1/6

3/5 - 4/7=21/35 - 20/35=1/35

5/7 - 1/6=30/42 - 7/42=23/42

3/4 + 4/5 =15/20+16/20=31/20=1 11/20

3/4+2/9=27/36+8/36=35/36

1/2-1/3=3/6-2/6=1/6;
3/5-4/7=21/35-20/35=1/35
5/7-1/6=30/42-7/42=23/42
3/+4/5=?
3/3/4+2/9=?