bonjour devoir maison peut on m aider svp. merçi

exercice 1

A=1/5x-4/3+7/2
A= -4/15+7/2=-8/30+105/30=97/30

B= 4/5 : -3/7-7/10
B= 4/5x7/-3-7/10
B= 28/-15 - 7/10
B= -56/30-21/30=-77/30

C= 13/7+ -8/7:-4/5
C=13/7 - 8/7x5/-4
C= 13/7-40/-28
C= 52/28-48/28=4/28=2/13

D= 7/3+3/2x-10/21
D = 7/3 -30/42
D=98/42-30/42
D= 68/42=34/21

Exercice 2

240x2/3=160 places occupées
240-160 = 80 places libres
80x3/5 = 48
80-48=32
il reste 32 places libres