Выполни действия: а)3+8 5/12 б)10 6/7-3 в)4 2/13+5 7/13 г)8 7/12-4 2/12

Вычислим значения выражения: 

а) 3 + 8 5/12 = 3 + (8 * 12 + 5)/12 = 3 + (96 + 5)/12 = 3 + 101/12 = (3 * 12 + 101)/12 = (36 + 101)/12 = 137/12 = 11 5/12; 

б) 10 6/7 - 3 = 10  +6/7 - 3 = (10 - 3) + 6/7 = 7 + 6/7 = 7 6/7; 

в) 4 2/13 + 5 7/13 = 4 + 2/13 + 5 + 7/13 = (4 + 5) + (2/13 + 7/13) = 9 + (2 * 1 + 7 * 1)/13 = 9 + (2 + 9)/13 = 9 + 11/13 = 9 11/13; 

г) 8 7/12 - 4 2/12 = 8 + 7/12 - (4 + 2/12) = 8 + 7/12 - 4 - 2/12 = (8 - 4) + (7/12 - 2/12) = 4 + (7 * 1 - 2 * 1)/12 = 4 + (7 - 2)/12 = 4 + 5/12 = 4 5/12.