Bonjour
1)
Multiplier par 3/7
7 * 3/7 = 21/7 = 3
Ajouter 5
3 + 5 = 8
Diviser par 1/5
8 : 1/5 = 8 x 5/1 = 40
2)
28/15 x 3/7 = 84/105 = 4/5
4/5 + 5 = 4/5 + 25/5 = 29/5
29/5 : 1/5 = 29/5 x 5/1 = 145/5 = 29.