(7/9-1/6): 2/9*21/22 7/8+5/8*1/3+2/3 (1/6+3/14): (5/21-1/14

(7/9 - 1/6) : 2/9 * 21/22 = 2 5/8
1) 7/9 - 1/6 = 14/18 - 3/18 = 11/18
2) 11/18 : 2/9 = 11/18 * 9/2 = 11/4
3) 11/4 * 21/22 = 21/8 = 2 5/8

7/8 + 5/8 * 1/3 + 2/3 = 1 3/4
1) 5/8 * 1/3 = 5/24
2) 7/8 + 5/24 = 21/24 + 5/24 = 26/24 = 1 2/24 = 1 1/12
3) 1 1/12 + 2/3 = 1 1/12 + 8/12 = 1 9/12 = 1 3/4

(1/6 + 3/14) : (5/21 - 1/14) = 2 2/7
1) 1/6 + 3/14 = 7/42 + 9/42 = 16/42 = 8/21
2) 5/21 - 1/14 = 10/42 - 3/42 = 7/42 = 1/6
3) 8/21 : 1/6 = 8/21 * 6/1 = 48/21 = 2 6/21 = 2 2/7