3 1/2 - 5/9 = 7/2- 5/9 =(7* 9 - 5 *2)/18 = 63/18 - 10/18 = 53/18 = 2 17/18
1 1/4 - 1/3 = 5/4 - 1/3 =(5 * 3 - 1 * 4)/12 = 15/12 - 4/12 = 11/12
1 13/15-2/5 = 28/15 - 2/5 = (28 *1- 2* 3)/15 =28/15 - 6/15 = 22/15 = 1 7/15
1 1/3 - 5/6 = 4/3 - 5/6 =(4 * 2 - 5* 1)/6 = 8/6 - 5/6 = 3/6 = 1/2
2 3/10-4/15=23/10-4/15 =(23 * 3-4 *2)/30 = 69/30-8/30 = 61/30 = 2 1/30
3 1/8 - 1/6 = 25/8 -1/6 =(25* 3 -1 *4)/24 = 75/24-4)/24 =71/24 = 2 23/24