Найдите значение числового выражение.(11/4÷21/2+33/7×15/9)÷5/12-81/5

1) 11/4 : 21/2 = 11/4 * 2/21 = 22/84 = 11/42
2) 33/7 * 15/9 = 11*15 / 7*3 = 165/21 = 55/7
3) 11/42 + 55/7 = 11/42 + 330/42 = 341//42
4) 341/42 : 5/12 = 341/42 * 12/5 = 682/35
5) 682/35 - 81/5 = 682/35 - 567/35= 115/35 = 23/7 = 3 2/7