(3 1/2 - 7/9) * 6/11 + (8/33 - 1/11) : 10/11 = 1 43/66
1) 3 1/2 - 7/9 = 3 9/18 - 14/18 = 2 27/18 - 14/18 = 2 13/18
2) 8/33 - 1/11 = 8/33 - 3/33 = 5/33
3) 2 13/18 * 6/11 = 49/18 * 6/11 = 49/33 = 1 16/33
4) 5/33 : 10/11 = 5/33 * 11/10 = 1/6
5) 1 16/33 + 1/6 = 1 32/66 + 11/66 = 1 43/66
