1. 7/9 + 5/6 - 2 7/12 = 28/36 + 30/36 - 93/36 = 35/36
2. 2 2/3 : 3 1/3 = х : 3,5
8/3 : 10/3 = х : 35/10
8/10 = х : 35/10
8/10 * 35/10 = х
х = 28/10
х = 2,8
3. |5/9| - |-2/3| = |5/9| - |6/9| = - |1/9|
Задача:
1 и 2 день:
36% + 52% = 88%
3 день - 100% - 88% = 12%
54 км - 12%
х км - 100%
х = 54 * 100% / 12% = 450 км