4,25 + 1 11/12 - 8/15 = 5 19/30
1) 0,25 = 25/100 = 1/4 = 3/12
4,25 + 1 11/12 = 4 3/12 + 1 11/12 = 5 14/12 = 5 7/6 = 6 1/6
2) 6 1/6 - 8/15 = 6 5/30 - 16/30 = 5 35/30 - 16/30 = 5 19/30
ответ: 5 целых 19/30.
