22 - 4 = 18

5/7 - 0 = 5/7

18 + 5/7 = (18 * 7 + 5) / 7 = 131/7

5,72 - 4,28 = 1,44

131/7 - 1,44 = (131 - 1,44*7) / 7 = (131 - 10,08) / 7 = 120,92 / 7 = 17,28

Ответ: 17,28