Bonjour pouvez vous m'aider svp je ne comprends pas​

Réponse :

Explications étape par étape

Bonjour

A = -8/7 + 11/3

A = -(8 x 3)/(7 x 3) + (11 x 7)/(3 x 7)

A = -24/21 + 77/21

A = 53/21

B = 7/8 x 4/49

B = 4/8 x 7/49

B = 4/(2 x 4) x 7/(7 x 7)

B = 1/2 x 1/7

B = 1/14

C = 3/4 - 2/10

C = (3 x 5)/(4 x 5) - (2 x 2)/(10 x 2)

C = 15/20 - 4/20

C = 11/20

D = (45/12) / (5/48)

D = 45/12 x 48/5

D = 45/5 x 48/12

D = (9 x 5)/5 x (4 x 12)/12

D = 9 x 4

D = 36

E = 25/(-16) x (-21/35)

E = -25/16 x -21/35

E = 25/35 x 21/16

E = (5 x 5)/(7 x 5) x 21/16

E = 5/7 x 21/16

E = 21/7 x 5/16

E = (3 x 7)/7 x 5/16

E = 3 x 5/16

E = 15/16

F = (-5)/(-4) : (-20/12)

F = 5/4 x -12/20

F = 5/20 x -12/4

F = 5/(5 x 4) x (-3 x 4)/4

F = 1/4 x -3

F = -3/4

Exercice 2 :

A = 3/4 - 5/2 x 7/3

A = 3/4 - 35/6

A = (3 x 3)/(3 x 4) - (35 x 2)/(6 x 2)

A = 9/12 - 70/12

A = 61/12

B = 7/6 - 8/3 x 5/4

B = 7/6 - 8/4 x 5/3

B = 7/6 - 2 x 5/3

B = 7/6 - 10/3

B = 7/6 - (10 x 2)/(3 x 2)

B = 7/6 - 20/6

B = -13/6

C = (5/4 + 3/24) / (2 - 1/3)

C = [(5 x 6)/(4 x 6) + 3/24] / [(2 x 3)/3 - 1/3]

C = (30/24 + 3/24) / (6/3 - 1/3)

C = 33/24 / (5/3)

C = 33/23 x 3/5

C = 99/115

Exercice 3 :

A = a + b x c

B = a x (b + c)

a = 1/6 ; b = 2/6 et c = 3/4

A = 1/6 + 2/6 x 3/4

A = 1/6 + 2/4 x 3/6

A = 1/6 + 1/2 x 1/2

A = 1/6 + 1/4

A = 2/12 + 3/12

A = 5/12

B = 1/6 x (2/6 + 3/4)

B = 1/6 x (4/12 + 9/12)

B = 1/6 x 13/12

B = 13/72