Sagot :

Réponse :

Explications étape par étape

Bonjour

Donner le résultat sous la forme d’une fraction irréductible :

7/5 x 3/4 + 7/3 x 4/5

= (7 x 3)/(5 x 4) + (7 x 4)/(3 x 5)

= 21/20 + 28/15

= (21 x 3)/(20 x 3) + (28 x 4)/(15 x 4)

= 63/60 + 112/60

= (63 + 112)/60

= 175/60

= (5 x 35)/(5 x 12)

[tex]\bf{= 35/12}[/tex]

(7 - 3 x 2)/12 - (3 + 3 x 3)/(5 x 5 - 5)

= (7 - 6)/12 - (3 + 9)/(25 - 5)

= 1/12 - 12/20

= (1 x 5)/(12 x 5) - (12 x 3)/(20 x 3)

= 5/60 - 36/60

[tex]\bf{= -31/60}[/tex]

Bonjour

1)

7/5 x 3/4 + 7/3 x 4/5

= 21/20 + 28/15

= (21 x 3) / (20 x 3) + (28 x 4) / (15 x 4)

= 63/60 + 112/60

= 175/60

= (5 x 35) / (5 x 12)

= 35/12

2)

(7 - 3 x 2) / 12 - (3 + 3 x 3) / (5 x 5 - 5)

= (7 - 6)/12 - (3 + 9) / (25 - 5)

= 1/12 - 12/20

= (1 x 15) / (12 x 5) - (12 x 3) / (20 x 3)

= 15/60 - 36/60

= - 21/60

= (3 x - 7) / (3 x 20)

= - 7/20.