bonjour j ai besoin d aide merci d avance exercice 49 calculer et simplifier la fraction obtenue a. 3\4 - 11\12 b. 3\4 + 11\12 c. 5\6 - 7\18 exercice

bonjour ♥

ex 49 :

= 3/4 - 11/12
= 9/12 - 11/12
= -2/12
= -1/6


= 3/4 + 11/12
= 9/12 + 11/12
= 20/12
= 10/6
= 5/3


= 5/6 - 7/18
= 15/18 - 7/18
= 8/18
= 4/9

ex 53 :

¤ le multiple commun est 35

¤= 8/5 - 3/7
= 56/35 - 15/35
= 41/35

= 8/5 + 3/7
= 56/35 + 15/35
= 71/35

Coucou

Exo 49

a. 3 / 4 - 11 / 12
= (3 x 3) / (4 x 3) - 11 / 12
= 9 / 12 - 11 / 12
= (9 - 11) / 12
= - 2 / 12
= - (2 / 2) / (12 / 2)
= - 1 / 6

b. 3 / 4 + 11 / 12
= (3 x 3) / (4 x 3) + 11 / 12
= 9 / 12 + 11 / 12
= (9 + 11) / 12
= 20 / 12
= (20 / 4) / (12 / 4)
= 5 / 3

c. 5 / 6 - 7 / 18
= (5 x 3) / (6 x 3) - 7 / 18
= 15 / 18 - 7 / 18
= (15 - 7) / 18
= 8 / 18
= (8 / 2) / (18 / 2)
= 4 / 9

Exo 53 

1) Multiple commun : 35

2) 
a. 8 / 5 - 3 / 7
= (8 x 7) / (5 x 7) - (3 x 5) / (7 x 5)
= 56 / 35 - 15 / 35
= (56 - 15) / 35
= 41 / 35

b. 8 / 5 + 3 / 7
= (8 x 7) / (5 x 7) + (3 x 5) / (7 x 5)
= 56 / 35 + 15 / 35
= (56 + 15) / 35
= 71 / 35

Voilà j'espère avoir pu t'aider ^^