A = 3/14 + 5/21
A = 19/42
B = 3/4 + 2/5 × 10/3
B = 25/12
C = -8/45 × 27/32
C = -3/+20
D = 5/3 - 2/3 ÷ 7/4
D =9/7
E = (2/3 - 1/4) ÷ (2/3 + 1/4)
E= 5/11
Exercice 5
a = 15/26 × 39/25 × 2/9
a = 1/5
b= 34/35 ÷ 18/49
b= 119/45
c= (1/2 - 1/3) × (3/4 - 4/3)
c= - 7/72
d= (1/2 - 2/3) ÷ (3/4 + 4/5)
d = - 10/93
Exercice 6
A = 2/3 - 3/4 × 7/5
A = -23/60
B = (2/3) × (-9) × 12/14
B = -36/7
C = 5 - 7/8 + 2/3
C = 115/24
D = 1/2 + 2/3 / 3/4 - 4/5
D = 70/-3
