Выполните сложение:
=31
=13 3/7
=28 4/9
1) 18 5/8 + 12 3/8 = 30 8/8 = 31 2) 6 4/7 + 6 6/7 = 12 10/7 = 13 3/7 3) 1/9 + 9 5/9 + 18 7/9 = 27 13/9 = 28 4/9