Bonjour,
Exercice 1 :
a) 75 x 4/5 = 300/5 = 60 cm
b) 60 x 4/5 = 240/5 = 48 cm
c) 48 x 4/5 = 192/5 = 38,4 cm
d) 38,4 x 4/5 x 4/5 = 153,6/5 x 4/5 = 614,4/25 = 24,576 cm
Exercice 3 :
1) 1 - [2/7 - (1/4 x (1 - 2/7))]
= 1 - [2/7 - (1/4 x (7/7 - 2/7))]
= 1 - [2/7 - (1/4 x 5/7)]
= 1 - (2/7 - 5/28)
= 1/1 - (8/28 - 5/28)
= 28/28 - 3/28
= 25/28
Il lui reste 25/28 de sa reserve de noisettes pour finir l'hiver.
2) 1 - 4/5 x 25/28
= 140/140 - 100/140
= 40/140
Oui, il lui reste des noisettes Ă la fin de l'hiver
