219. Выполните сложение: а) 4 5/17 + 8/17; б) 3 5/21 + 4 8/21; в) 13 + 12 11/12; г) 9 5/6 + 7; д) 3 12/23 + 4 11/23; e) 7 15/19 + 4 14/19.

а) 4 5/17 + 8/17 = 4 + (5/17 + 8/17) = 4 + 13/17 = 4 13/17 б) 3 5/21 + 4 8/21 = (3 + 4) + (5/21 + 8/21) = 7 + 13/21 = 7 13/21 в) 13 + 12 11/12 = (13+12) + 11/12 = 25 + 11/12 = 25 11/12 г) 9 5/6 + 7 = (9 + 7) + 5/6 = 16 + 5/6 = 16 5/6 д) 3 12/23 + 4 11/23 = (3 + 4) + (12/23 + 11/23) = 7 + 23/23 = 7 + 1 = 8 е) 7 15/19 + 4 14/19 = (7+4) + (15/19+14/19) = 11+29/19 = 11+1 10/19 = 12 10/19