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