Найди значение выражения:
1/2+3/5-2/3=...
5/9+1/6+3/4=...
1/4+1/5-3/10=...

1/2+3/5-2/3=15/30 + 18/30 - 20/30 = 13/30

5/9+1/6+3/4=20/36 + 6/36 +27/36 = 53/36 = 1 17/36

1/4+1/5-3/10=5/20 + 4/20 - 6/20 = 3/20