On calcule:
a/b = a x 1/b
2/9|-5/3 = 2/9×-3/5 = -6/45
3/5|1/5 = 3/5×5 = 3
-1/4|3 = -1/4×1/3 = -1/12
22/7|-11 = 22/7×-1/11 = -2/7