5) Находим общий множитель - 24
8/24 + 9/24 = 17/24
24/24 - 17/24 = 7/24
6) 1. 1 3/4 - 1/12 = 1 9/12 - 1/12 = 1 8/12 =1 2/3
2. 4/21 + 1 2/3 = 4/21 + 5/3 = 4/21 + 35/21 = 39/21 =1 18/21 = 1 6/7
3. 1 6/7 - 5/14 = 1 12/14 - 5/14 = 1 7/14 = 1 1/2
4. 1 1/2 + 1 2/3 = 1 3/6 + 1 4/6 = 3 1/6
7) 5 3/4 + 2/4 = 6 1/4 - вторая сторона
(5 3/4 + 6 1/4)*2= 24 м