3 1/2
Пошаговое объяснение:
1) 1 1/2 + 3/5 = 1 5/10 + 6/10 = 1 11/10 = 2 1/10
2) 5 1/4 : 2 1/10 = 21/4 : 21/10 = 21/4 * 10/21 = 10/4 = 2 2/4 = 2 1/2
3) 5/6 - 3/4 = 10/12 - 9/12 = 1/12
4) 1/12 * 12 = 12/12 = 1
5) 2 9/13 : 5 = 35/13 * 1/5 = 7/13 * 1/1 = 7/13
6) 7/13 - 7/13 = 0
7) 2 1/2 + 1 - 0 = 3 1/2
