Вычислите
1) 11/12-1/20-1/30
2)2/3-5/24-3/10
3)4/5-4/45-7/25

1) 11/12 - 1/20 - 1/30

  11/12 - 1/20 = 220/240 - 12/240 = 208/240 = 13/15

  13/15 - 1/30 = 26/30 - 1/30 = 25/30 = 5/6

  2/3 - 5/24 = 16/24 - 5/24 = 11/24

2) 2/3 - 5/24 - 3/10

   11/24 - 3/10 = 110/240 - 72/240 = 38/240 = 19/120

3) 4/5 - 4/45 - 7/25

   4/5 - 4/45 = 36/45 - 4/45 = 32/45

   32/45 - 7/25 = 160/225 - 63/225 = 97/225