Odpowiedź:
2 i 3/20 + 1/4 = 2 i 3/20 + 5/20 = 2 i 8/20 = 2 i 2/5
1 i 5/18 + 2 i 4/9 + 5/6 = 1 i 5/18 + 2 i 8/18 + 15/18 = 3 i 28/18 = 4 i 10/18 = 4 i 5/9
3 i 1/2 + 2 i 3/4 + 1 i 1/3 = 3 i 6/12 + 2 i 9/12 + 1 i 4/12 = 6 i 19/12 = 7 i 7/12
2 i 1/20 - 3/4 = 2 i 1/20 - 15/20 = 1 i 21/20 - 15/20 = 1 i 6/20 = 1 i 3/10
1 i 7/18 - 2 i 2/9 = 1 i 7/18 - 2 i 4/18 = -1 i 3/18
2 i 1/7 - 5 i 2/3 = 2 i 3/21 - 5 i 14/21 = 1 i 24/21 - 5 i 14/21 = - 4 i 10/21
