4Целые2/5:(1целая1/2-2/5)+(3/4+5/6):4целые3/4

Решим пример по действиям:

1) 1 1/2 - 2/5 = (1 * 2 + 1)/2 - 2/5 = 3/2 - 2/5 = 15/10 - 4/10 = (15 - 4)/10 = 11/10;

2) 4 2/5 : 11/10 = (4 * 5 + 2)/5 * 10/11 = (20 + 2)/5 * 10/11 = 22/5 * 10/11 = (22 * 10)/(5 * 11) = 2 * 2 = 4;

3) 3/4 + 5/6 = 9/12 + 10/12 = (9 + 10)/12 = 19/12;

4) 19/12 : 4 3/4 = 19/12 : (4 * 4 + 3)/4 = 19/12 : 19/4 = 19/12 * 4/19 = (19 * 4)/(12 * 19) = 4/12 = 1/3;

5) 4 + 1/3 = 12/3 + 1/3 = (12 + 1)/3 = 13/3.

Ответ: 13/3.