Bonjour a tous et a toute matière Math classe de 3 eme qui peut aider pour l exercice 2 et le bonus merci d avance

Réponse :

Bonjour

Explications étape par étape

Exercice 2

A = 11/8 + 7/8 X 2/7

A = 11/8 + 14/56

A = 11/8 X 7/7 + 14/56

A = 77/56 + 14/56

A = 91/56

B= 2/7 -15/7 +5/4

B = 2/7 X 4/4 -15/7 X 4/4 +5/4 X 7/7

B = 8/28 -60/28 + 35/28

B = 43/28 -60/28 = 17/28

C = 9/7 -2/5 X 15/8

C = 9/7 -30/40

C = 9/7 X 40/40 -30/40 X 7/7

C = 360/280 - 210/280

C = 150/280 = 15/28

D = 5/4 : ( 4/3 -1/2)

D = 5/4 : ( 4/3 X 2/2 -1/2 X 3/3)

D = 5/4 : ( 8/6 -3/6)

D = 5/4 : 5/6

D = 5/4 X 6/5

D = 30/20 = 3/2

E = 5/7 + 1/7 X ( 5 +1/2)

E = 5/7 +1/7 X (10/2 +1/2)

E = 5/7 +1/7 X 11/2

E = 5/7 +11/14

E = 5/7 X 2/2 +11/14

E = 10/14 +11/14 = 21/14 = 3/2

F = 4/3 -1 : 7/6 -2 = 1/3 -3/3 : 7/6 -12/6 = 1/3 : -5/6 = 1/3 X -6/5 = -6/15 = -2/5

BONUS

Quentin court 3/4 d'une heure, soit 45 minutes

1 heure et demie d'escalade = 90 minutes

+ 50 minutes de badmiton, cela donne

45 + 90 + 50 = 185  = 3 heures 5 minutes