1/2 + 3/4 = 2/4 + 3/4 = 5/4 = 1 i 1/4
3/4 - 3/8 = 6/8 - 3/8 = 3/8
1 i 3/5 + 2 i 4/15 = 1 i 9/15 + 2 i 4/15 = 3 i 13/15
2 i 1/9 - 1 i 5/6 = 2 i 2/18 - 1 i 15/18 = = 1 i 20/18 - 1 i 15/18 = 5/18
10 - 3 i 1/4 - 1 i 3/5 = 10 - 3 i 5/20 - 1 i 12/20 = 6 i 15/20 - 1 i 12/20 = 5 i 3/20
