Réponse :

Bonsoir

Explications étape par étape

Fractions

A = 1/3 + 5/9

A = 1/3 X 3/3 +5/9

A = 3/9 +5/9

A = 8/9

B = 4/7 -4/5

B = 4/7 X 5/5 -4/7 X 7/7

B = 20/35 -28/35

B = -8/35

C = -9/2 X 5/7

C = -45/14

D = 8/5 : 7/3

D = 8/5 X 3/7

D = 24/35

E = 1/2 - (1/3 X 6/7 +2)

E = 1/2 - ( 6/21 +2 X 21/21 )

E = 1/2 - (6/21 +42/21)

E = 1/2 - (48/21)

E = 1/3 -48/21

E = 1/3 X 7/7 -48/21

E = 7/21 -48/21

E = -41/21

F = 3 -20/21 X 7/5

F = 3 - 140/105

F = 3 X 105/105 -140/105

F = 315/105 -140/105

F = 175/105

F = 35/21

F = 5/3