bonjour je n'arrive pas à résoudre ces fractions pouvez-vous m'aider ​

Bonjour,

a. - 7/25 x - 5/8

= 35/200

= (5 x 7) / (5 x 40)

= 7/40

b. 18/- 49 x 14/27

= - 252/1 323

= (63 x - 4) (63 x 21)

= - 4/21

c. 45/28 x 7/- 15

= - 315/420

= (105 x - 3) / (105 x 4)

= - 3/4

d. - 2/6 x (- 21/11)

= 42/66

= (6 x 7) / (6 x 11)

7/11

e. 21/32 x 108/49

= 2 268/1 568

= (28 x 81) / (28 x 56)

= 81/56

f. - 26 x - 5/39

= 130/39

= (13 x 10) / (13 x 3)

= 10/3

g. 8/5 x - 5/21 x (- 9/16)

= - 40/105 x - 9/16

= 360/1 680

= (120 x 3) / (120 x 14)

= 3/14

h. 56/- 5 x 30/21 x 7/10

= - 1 680/105 x 7/10

= - 11 760/1 050

= (210 x - 56) / (210 x 5)

= - 56/5.

Réponse :

Explications étape par étape

Bonjour

-7/25 x -5/8

= 5/25 x 7/8

= 1/5 x 7/8

= 7/40

18/-49 x 14/27

= -14/49 x 18/27

= -(2 x 7)/(7 x 7) x (2 x 9)/(3 x 9)

= -2/7 x 2/3

= -4/21

45/28 x 7/-15

= -45/15 x 7/28

= (-3 x 15)/15 x 7/(7 x 4)

= -3 x 1/4

= -3/4

-2/6 x (-21/11)

= 2/(2 x 3) x 21/11

= 1/3 x (3 x 7)/11

= 3/3 x 7/11

= 7/11

21/32 x 108/49

= 108/32 x 21/49

= (4 x 27)/(4 x 8) x (3 x 7)/(7 x 7)

= 27/8 x 3/7

= 81/56

-26 x -5/39

= 26/39 x 5

= (2 x 13)/(3 x 13) x 5

= 2/3 x 5

= 10/3

8/5 x -5/21 x (-9/16)

= 5/5 x 8/16 x 9/21

= 8/(2 x 8) x (3 x 3)/(3 x 7)

= 1/2 x 3/7

= 3/14

56/-5 x 30/21 x 7/10

= -30/10 x 56/5 x 7/21

= -(3 x 10)/10 x 56/5 x 7/(3 x 7)

= -3 x 56/5 x 1/3

= -3/3 x 56/5

= -56/5