(3 1/4 + 1 1/6 : 1 5/9) : 2 2/7 + 5 1/9: 7 2/3=2 5/12
1) 1 1/6 : 1 5/9= 7/6 : 14/9 = 7/6 ×9/14= 3/4
2) 3 1/4 + 3/4 = 4
3) 4 : 2 2/7= 4/1 : 16/7 = 4/1 ×7/16= 7/4= 1 3/4
4) 5 1/9 : 7 2/3 = 46/9 × 3/23 = 2/3
5) 1 3/4 + 2/3 = 1 + (9/12+8/12)= 1 + 1 5/12= 2 5/12