Odpowiedź:
5/8 - 0 = 5/8
1 * 7 i 8/9 = 1 * 71/9 = 71/9 = 7 i 8/9
0 : 3/4 = 0
1 + 2/3 = 1 i 2/3
0 * 4/7 = 0
1 - 6/13 = 13/13 - 6/13 = 7/13
zad 14
8 i 3/4 + 1 i 1/4 : 3 i 3/4 = 8 i 3/4 + 5/4 * 4/15 = 8 i 3/4 + 1/3 = 8 i 9/12 - 4/12 = 8 i 5/12
(4 i 2/5 - 2 i 3/4) * (2/3 + 1/11) = (4 i 8/20 - 2 i 15/20) * (22/33 + 3/33) = (3 i 28/20 - 2 i 15/20) * 25/33 = 1 i 13/20 * 25/33 = 33/20 * 25/33 = 5/4 = 1 i 1/4
zad 15
5 i 2/3 - 2 i 3/4 = 5 i 8/12 - 2 i 9/12 = 4 i 20/12 - 2 i 9/12 = 2 i 11/12
6 i 1/2 - 2 i 7/9 = 6 i 9/18 - 2 i 14/18 = 5 i 27/18 - 2 i 14/18 = 3 i 13/18
1 i 1/5 * 2 i 2/9 = 6/5 * 20/9 = 8/3 = 2 i 2/3
2/5 : 8 = 2/5 * 1/8 = 1/20
