(24 4/9 : 8 - 15 : 7 1/5) · 9 - 1 1/4 = 7 1/2

1) 24 4/9 : 8 = 220/9 · 1/8 = (55·1)/(9·2) = 55/18 = 3 1/18

2) 15 : 7 1/5 = 15 : 36/5 = 15/1 · 5/36 = (5·5)/(1·12) = 25/12 = 2 1/12

3) 3 1/18 - 2 1/12 = 3 2/36 - 2 3/36 = 2 38/36 - 2 3/36 = 35/36

4) 35/36 · 9/1 = (35·1)/(4·1) = 35/4 = 8 3/4

5) 8 3/4 - 1 1/4 = 7 2/4 = 7 1/2

Ответ: 7 целых 1/2 (или 7,5 в десятичных дробях).