Пошаговое объяснение:
1) 5/8+ 3/8 = (5+3)/8 = 8/8 =1
2)8/15+2/15 = (8+2)/15 = 10/15 = 2/3
3)17/25-12/25 = (17-12)/25 = 5/25 = 1/5
4) 28/45-13/45 = (28-13)/45 = 15/45 = 1/3
1)8/8
2)2/3
3)1/5
4)1/3
правильно
