Réponse :
bonjour
a = 4 x 12 = 48
a = 28 + 20 = 48
b = 12 + 15 = 27
b = 3 ( 4 + 5) = 3 x 9 = 27
c = 13 x 2 = 26
c = 16 + 10 = 26
d = 70 - 14 = 56
d = 7 ( 10 - 2 ) = 7 x 8 = 56
e = 5 x 6 = 30
e = 40 - 10 = 30
f = 680 - 280 = 400
f = 20 ( 34 - 14 ) = 20 x 20 = 400
Explications étape par étape :
