oblicz.

1. 2 1/3+6 2/3
2. 6 3/5- 8 4/5
3. 1 1/2+ 1/3
4. 5 2/3+ 1/2
5. 2 3/4- 4 1/2
6. 5 1/4- 4 2/3
7. (2/3*4/9): 1/6
8. (5/8*15/4): 6/5
9. (1/2*1/3): 1/6
10. (2/3*5/6): 8/15
11. (1 2/3: 8 4/7): 6/7
12. (2 6/7:1 3/7)* 1/2 ​