Bonjour,
2/5 + 1/4 = 8/20 + 5/20 = 13/20
20/20 - 13/20 = 7/20
7/20 -> 770
1/20 -> 770/7
20/20 -> (770*20)/ 7
=> 2 200€
2/3 + 400 -> 4/5
4/5 - 2/3 = 12/15 -10/15 = 2/15
2/15 -> 400
1/15 -> 400/2
15/15 -> (400* 15)/2
=> 3 000L
