1. -3,9+8,6+4,7+3,9-4,7=8,6
2. 4 3/8 - 3 3/7 - 9 5/10 + 5 1/8= - 3 3/7 + 9 1/2 - 9 1/2 = - 3 3/7
3. 4 9/14 - 5/12 - 3 3/14 - 3 1/12 + 1 1/14 = 2 1/2 - 3 1/2
4. 3 1/3 - 8/10 ( или 4/5) - 2 3/4 + 2 1/2 + 3/10 + 1 7/12 = - 1/2 + 7/12 + 2 1/2 + 1 7/12 = 3 + 2 1/6 = 5 1/6