- 56/49 =( - 7 x 8) sur ( 7 x 7) = - 8/7
45/-63 = 9 x 5 sur - 9 x 7 = - 5/7
44/33 = 4 x 11 sur 3 x 11 = 4/3
80/-48 = 5 x 16 sur - 3 x 16 = - 5/3
2.5 = 60/24
- 5/4 = - 30/24
1.3/- 2.4 = - 13/24
1/4 - 5/4 = - 1/4
5/33 + ( - 2/11) = 5/33 - 6/33 = - 1/33
7/9 - ( - 2/18) = 14/18 + 2/18 = 16/18 = 8/9
- 6/5 + 3 = - 5/5 + 15/5 = 10/5 = 2