19(целых) 17/27 + (21 16/27 - 19 20/27) - 17 19/27

Question

19(целых) 17/27 + (21 16/27 - 19 20/27) - 17 19/27

Answer 1

1) 21 16/27 - 19 20/27 = 1 23/27
2) 19 17/27 + 1 23/27 = 21 13/27
3) 21 13/27 - 17 19/27 = 3 21/27