(1)5/9 + 3/4= (2)6 7/8 - 3/4= (3)2/5 + 7/9= (4)4 17/18 - 5/9= (5)4 2/3 * 1 2/7= (6) 11/12 * 3 3/7 + (3 1/6 - 2 7/15) : 2 6/7=