(23 целых 1/21: 1целая 3/7-5,5): 3,19-1целая17/18=? решите этот пример

(23 1/21 : 1 3/7 - 5,5) : 3,19 - 1 17/18 = 1 целая 7/18

1) 23 1/21 : 1 3/7 = 484/21 : 10/7 = 484/21 * 7/10 = (242*1)/(3*5) = 242/15 = 16 целых 2/15
2) 16 2/15 - 5,5 = 16 2/15 - 5 5/10 = 16 4/30 - 5 15/30 = 15 34/30 - 5 15/30 = 10 целых 19/30 = 319/30
3) 319/30 : 3,19 = 319/30 : 319/100 = 319/30 * 100/319 = 100/30 = 10/3 = 3 целых 1/3
4) 3 1/3 - 1 17/18 = 3 6/18 - 1 17/18 = 2 24/18 - 1 17/18 = 1 целая 7/18