7/9 + 2/5 = (35/45) + (18/45) = 53/45
1/12 + 3/4 = (1/12) + (9/12) = 10/12 = 5/6
2/5 + 4/9 = (18/45) + (20/45) = 38/45
7/9 + 2/5 = (35/45) + (18/45) = 53/45
1/12 + 3/4 = (1/12) + (9/12) = 10/12 = 5/6
2/5 + 4/9 = (18/45) + (20/45) = 38/45