((1 2/5)кв. : 1 2/5 - 5/6) * 4 2/7 + (28 - 27 6/7) * 53 = 10
1) (1 2/5)кв. : 1 2/5 = 1 2/5
2) 1 2/5 - 5/6 = 1 12/30 - 25/30 = 42/30 - 25/30 = 17/30
3) 17/30 * 4 2/7 = 17/30 * 30/7 = 17/7 = 2 3/7
4) 28 - 27 6/7 = 1/7
5) 1/7 * 53 = 53/7 = 7 4/7
6) 2 3/7 + 7 4/7 = 9 7/7 = 10