ответ: 7/20 и 5/12 = 21/60 и 25/60
3/16 и 7/12 = 9/48 и 28/48
1/12 и 2/9 = 3/36 и 8/36
1)7/20 и 5/12=21/60 25/60
2)3/16 и 7/12 9/48 и 28/48
3) 1/12 и 2/9 = 3/36 и 8/30
