Bonjour
a. 7/4 = (7 x 3) / (4 x 3) = 21/12
21/12 > 17/12 donc 7/4 > 17/12
b. 8/5 = (8 x 6) / (5 x 6) = 48/30
48/30 > 49/30 donc 8/5 < 49/30
c. 3/7 = (3 x 2) / (7 x 2) = 6/14
6/14 > 5/14 donc 3/7 > 5/14
d. 7/5 = (7 x 9) / (5 x 9) = 63/45
7/9 = (7 x 5) / (9 x 5) = 35/45
63/45 > 35/45 donc 7/5 > 7/9
e. - 10/7 = (- 10x 2) / (7 x 2) = - 20/14
- 3/2 = (- 3 x 7) / (2 x 7) = - 6/14
- 20/14 < - 6/14 donc - 10/7 < - 3/2
f. - 4/15 = (- 4 x 5) / (15 x 5) = - 20/75
- 6/25 = (- 6 x 3) / (25 x 3) = - 18/75
- 20/75 < - 18/75 donc - 4/5 < - 6/25.
