4*{2 1/2+1 3/4}-{6 2/3+4 4/5}: 2 по действиям

4 * (2 1/2 + 1 3/4) - (6 2/3 + 4 4/5) : 2 = 11 целых 4/15

1) 2 1/2 + 1 3/4 = 2 2/4 + 1 3/4 = 3 5/4 = 4 целых 1/4 = 17/4
2) 4 * 17/4 = 17
3) 6 2/3 + 4 4/5 = 6 10/15 + 4 12/15 = 10 22/15 = 11 целых 7/15 = 172/15
4) 172/15 : 2 = 172/15 * 1/2 = 172/30 = 5 22/30 = 5 целых 11/15
5) 17 - 5 11/15 = 16 15/15 - 5 11/15 = 11 целых 4/15

Пояснения:
4 целых 1/4 = (4*4+1)/4 = 17/4
11 целых 7/15 = (11*15+7)/15 = 172/15