Odpowiedź:
1 i 5/7 + 4/7 = 1 i 9/7 = 2 i 2/7
2 i 2/3 + 1 i 1/5 = 2 i 10/15 + 1 i 3/15 = 3 i 13/15
1 i 4/13 - 9/13 = 17/13 - 9/13= 8/13
6 i 8/9 - 4 i 2/3 = 6 i 8/9 - 4 i 6/9 = 2 i 2/9
zad 2
1/5 + 3/5 = 4/5
4 i 3/15 + 4 i 7/15 = 8 i 10/15 = 8 i 2/3
11/18 - 4/18 = 7/18
7 i 7/9 - 2 i 5/9 = 5 i 2/9
zad 4
1 i 1/7 + 3/5 = 1 i 5/35 + 21/35 = 1 i 26/35
2 i 3/4 + 1 i 2/3 = 2 i 9/12 + 1 i 8/12 = 3 i 17/12 = 4 i 5/12
4 i 3/4 - 1 i 2/5 = 4 i 15/20 - 1 i 8/20 = 3 i 7/20
5 i 1/4 - 3 i 1/2 = 5 i 1/4 - 3 i 2/4 = 4 i 5/4 - 3 i 2/4 = 1 i 3/4
