Réponse :
bonjour
7/20 + 7/10 = 7/20 + 14/20 = 21/20
7/10 + 16/40 = 28/40 + 16/40 = 44/40 = 11/10
4/5 + 7/20 = 16/20 + 7/20 = 23/20
4/5 + 16/40 = 32/40 + 16/40 =48/40 = 6/5
11/10 - 21/20 = 6/5 - 23/20
22/20 - 21/20 = 24/20 - 23/20
1/20 = 1 /20
Explications étape par étape :
