Пошаговое объяснение:

5 5/7 = (5*7 + 5)/7 = (35+5)/7 = 40/7

3 6/7 = (3*7 + 6)/7 = (21+6)/7 = 27/7

№1

5 5/7 - 3 6/7 = 4 12/7 - 3 6/7 = 1 6/7

№2

12 3/10 - 6 7/10 = 11 13/10 - 6 7/10 = 5 6/10 = 5 3/5