Réponse :
Explications étape par étape
Bonjour
39 Calculer
A= 5/2 + 3/4 + -7/8
A = (5 x 4)/(2 x 4) + (3 x 2)/(4 x 2) - 7/8
A = 20/8 + 6/8 - 7/8
A = 19/8
B= 4/15 + 2/5 - 7/30
B = (4 x 2)/(15 x 2) + (2 x 6)/(5 x 6) - 7/30
B = 8/30 + 12/30 - 7/30
B = 13/30
40 Recopier et compléter les égalités suivantes
A= 5/8 + 11/6 = .../24 + .../24 = .../...
A = (5 x 3)/(8 x 3) + (11 x 4)/(6 x 4)
A = 15/24 + 44/24
A = 59/24
B= 7/30 + 2/12 = .../60 + .../60 = .../...
B = (7 x 2)/(30 x 2) + (2 x 5)/(12 x 5)
B = 14/60 + 10/60
B = 24/60
B = (2 x 12)/(5 x 12)
B = 2/5
41 calculer
A = 5/4 + 1/6
A = (5 x 3)/(4 x 3) + (1 x 2)/(6 x 2)
A = 15/12 + 2/12
A = 17/12
B = 7/15 - 3/10
B = (7 x 2)/(15 x 2) - (3 x 3)/(10 x 3)
B = 14/30 - 9/30
B = 5/30
B = 5/(5 x 6)
B = 1/6
C = 5/8 + 5/12
C = (5 x 3)/(8 x 3) + (5 x 2)/(12 x 2)
C = 15/24 + 10/24
C = 25/24
