10 5/12 - 7 1/2 : (2 1/6 + 8/15) · 1 4/5 = 5 5/12
1) 2 1/6 + 8/15 = 2 5/30 + 16/30 = 2 21/30 = 2 7/10
2) 7 1/2 : 2 7/10 = 15/2 : 27/10 = 15/2 · 10/27 = (5·5)/(1·9) = 25/9
3) 25/9 · 1 4/5 = 25/9 · 9/5 = 25/5 = 5
4) 10 5/12 - 5 = 5 5/12
ответ: 5 целых 5/12.
10 5/12 - 7 1/2 : (2 1/6 + 8/15) · 1 4/5 = 5 5/12
1) 2 1/6 + 8/15 = 2 5/30 + 16/30 = 2 21/30 = 2 7/10
2) 7 1/2 : 2 7/10 = 15/2 : 27/10 = 15/2 · 10/27 = (5·5)/(1·9) = 25/9
3) 25/9 · 1 4/5 = 25/9 · 9/5 = 25/5 = 5
4) 10 5/12 - 5 = 5 5/12
ответ: 5 целых 5/12.