Sagot :
Réponse :
Explications étape par étape
Bonjour
A = 2/21 + 8/7 - 7/14
A = (2 x 2)/(21 x 2) + (8 x 6)/(7 x 6) - (7 x 3)/(14 x 3)
A = 4/42 + 48/42 - 21/42
A = (52 - 21)/42
A = 31/42
B = 48/25 - 1 + 7/5
B = 48/25 - 25/25 + (7 x 5)/(5 x 5)
B = 23/25 + 35/25
B = 58/25
C = 13/11 - 3/9
C = (13 x 9)/(11 x 9) - (3 x 11)/(9 x 11)
C = 117/99 - 33/99
C = 84/99
C = (3 x 28)/(3 x 33)
C = 28/33
D = 7/12 + 1/6 - (3/8 - 1/4)
D = 7/12 + 2/12 - (3/8 - 2/8)
D = 9/12 - 1/8
D = (9 x 2)/(12 x 2) - (1 x 3)/(8 x 3)
D = 18/24 - 3/24
D = 15/24
D = (3 x 5)/(3 x 8)
D = 5/8