Bonjour
a.
1/13 < 3/13 < 5/13 < 11/13 < 19/13 < 24/13
b.756
15/7 = (15 x 108) / (7 x 108) = 1 620/756
17/4 = (17 x 189) / (4 x 189) = 3 213/756
17/2 = (17 x 378) / (2 x 378) = 6 426/756
17/21 = (17 x 36) / (21 x 36) = 612/756
17/7 = (17 x 108) / (7 x 108) = 1 836/756
17/54 = (17 x 14) / (54 x 14) = 238/756
Donc :
17/54 < 17/21 < 15/7 < 17/7 < 17/4 < 17/2.
