Выполните действие: 2 целых 3/4:( 1 целых 1/2-2/5)+(3/4+5/6):3 целых 1/6

Выполним действия:

2 3/4 : (1 1/2 - 2/5) + (3/4 + 5/6) : 3 1/6 = 3;

1) 1 1/2 - 2/5 = 1 + 1/2 - 2/5 = 1 + 5/10 - 4/10 = 1 + (5 - 4)/10 = 1 + 1/10 = 1 1/10;

2) 3/4 + 5/6 = (3 * 3)/12 + (5 * 2)/12 = 9/12 + 10/12 = (9 + 10)/12 = 19/12 = 1 7/12;

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

4) 1 7/12 : 3 1/6 = 19/12 : 19/6 = 19/12 * 6/19 = (19 * 6)/(6 * 2 * 19) = 1/2;

5) 2 1/2 + 1/2 = 2 + 1/2 + 1/2 = 2 + (1 + 1)/2 = 2 + 2/2 = 2 + 1 = 3.