svp j'ai besoin d'aide pour les dernierr exercices

Bonjour

A = 1/2 +3/2 x 7/3
A = 1/2 + 21/6
A = 3/6 + 21/6 = 24/6 = 4

B = (1/2 +3/2) x 7/3
B = 4/2 + 7/3
B = 28/6 = 14/3

C = 20/9 -5/3 x 2/3
C = 20/9 - 10/9
C = 10/9

D = (20/9 - 5/3) x 2/3
D = (20/9 - 15/9) x 2/3
D = 5/9 x 2/3
D = 10/27

Paul
- lu le lundi : 4/7
- reste 7/7 -4/7 = 3/7
- lu mardi : 2/3 x 3/7 = 6/ 21
- lundi + mardi : 4/7 + 6/21 = 12/21 + 6/21 = 18/21
- reste à lire : 3/21 ou 1/7