(5,4 - 2 1/3) : 7 2/3 = (5 4/10 - 2 1/3) : 7 2/3 = (5 2/5 - 2 1/3) : 7 2/3 = (5 6/15 - 2 5/15) : 23/3 = 3 1/15 : 23/3 = 46/15 * 3/23 = 2/5 = 0,4. (2 1/3 + 0,25) * 0,12 = (2 1/3 + 1/4) * 12/100 = (2 4/12 + 3/12) * 3/25 = 2 7/12 * 3/25 = 31/12 * 3/25 = 31/100 = 0,31. (7,6 - 4 3/4) : 1,9 = (7,6 - 4,75) : 1,9 = 2,85 : 1,9 = 1,5. Ответ: 1. 0,4; 2. 0,31; 3. 1,5.