57. Выполните сложение или вычитание:

Для сложения и вычитания дробей нужно привести их к общему знаменателю. Первый столбик: 1/3 + 3/8 = 8/24 + 9/24 = 17/24 2/7 + 5/14 = 4/14 + 5/14 = 9/14 3/5 + 4/15 = 9/15 + 4/15 = 13/15 1/8 + 3/16 = 2/16 + 3/16 = 5/16 2/9 + 5/18 = 4/18 + 5/18 = 9/18 = 1/2 Второй столбик: 17/33 - 5/22 = 34/66 - 15/66 = 19/66 27/76 - 0 = 27/76 9/20 + 5/8 = 18/40 + 25/40 = 43/40 = 1 3/40 2/7 + 13/28 = 8/28 + 13/28 = 21/28 = 3/4 5/13 - 14/39 = 15/39 - 14/39 = 1/39 Третий столбик: 1 17/33 + 5/22 = 1 34/66 + 15/66 = 1 49/66 1 5/12 - 7/10 = 1 25/60 - 42/60 = 85/60 - 42/60 = 43/60 7 7/8 - 1 9/10 = 7 35/40 - 1 36/40 = 6 75/40 - 1 36/40 = 5 39/40 12 3/10 - 5 11/15 = 12 9/30 - 5 22/30 = 11 39/30 - 5 22/30 = 6 17/30 7 7/15 - 1 3/20 = 7 28/60 - 1 9/60 = 6 19/60 Четвертый столбик: 8/13 - 1/26 = 16/26 - 1/26 = 15/26 7/15 - 7/30 = 14/30 - 7/30 = 7/30 2/19 - 1/38 = 4/38 - 1/38 = 3/38 5/7 - 3/14 = 10/14 - 3/14 = 7/14 = 1/2 4/21 - 1/7 = 4/21 - 3/21 = 1/21 7/20 + 11/50 = 35/100 + 22/100 = 57/100 Пятый столбик: 5/8 - 2/7 = 35/56 - 16/56 = 19/56 3/4 + 5/12 = 9/12 + 5/12 = 14/12 = 7/6 = 1 1/6 15/23 - 27/46 = 30/46 - 27/46 = 3/46 9/25 - 14/117 = 1053/2925 - 350/2925 = 703/2925 (или 9/25 - 14/117 = 0.36 - 0.1196 = 0.2404) 17/35 - 13/28 = 68/140 - 65/140 = 3/140 1 - 2/7 = 5/7 Шестой столбик: 5 1/9 + 3 2/5 = 5 5/45 + 3 18/45 = 8 23/45 3 3/8 + 1 5/12 = 3 9/24 + 1 10/24 = 4 19/24 62 2/3 - 3 5/8 = 62 16/24 - 3 15/24 = 59 1/24 12 - 10 7/9 = 11 9/9 - 10 7/9 = 1 2/9 18 - 11 8/13 = 17 13/13 - 11 8/13 = 6 5/13 15 3/17 - 4 = 11 3/17