Bonjour,
Exercice 53
-4/45 + 16/15 = -4/45 + 48/45 = 44/45
-5/6 -1518 = -15/18 -15/18 = -30/18 = -10/2 = -5
12 - 3/4 = 48/4 - 3/4 = 45/4
1 -7/4 = 4/4 -7/4 = -3/4
Exercice 54
A=
2/(3/5) = 2*5/3 = 10/3
B=
(2/3) / 5 = 2/(3*5) = 2/15
C=
(2/3) / (7/11) = (2*11)/(3*7) = 22/21
Sur ta feuille, tu remplaces / par :
