Bonjour,
1)
2/3 =8/12
3/5 = 15/25
4/36 = -1/-9
49/63 = 7/9
2)
7/3 = 7°/30
8/5 = 48/30
13/10 = 39/30
5/6 = 25/30
3)
3/4 = 12/16
-7/8 = -14/16
14/32 = 7/16
4/25 = 16/100
13/20= 65/100
2/40 = 5/100
-71/10 = -7 100/ 1 000
-3/50 = -60/1 000
13/25 =520/ 1 000