Aider moi svp merci d avvance

Bonsoir

Exercice I

A =( 4/3 -1) :( 7/6 - 2)
= (4/3 - 3/3) : (7/6 - 12/6)
= 1/3 : - 5/6
= 1/3 x - 6/5 =  - 6/15 = - 2/5

B = (2/3 +1/2) : (12/9 - 1/3)
B = ( 4/6 + 3/6) : ( 12/9 - 3/9)
= 7/6 : 9/9 = 7/6 x 1 = 7/6

N°2
(-3/4 +1/2) : (2/5 -5/2)
(-3/4 + 2/4) : (4/10 - 25/10)
-1/4 : - 21/10 = -1/4 x - 10/10 = -1/4 x -1 = 1/4

(1 - 1/3 +1/4) : ( 1 + 1/3 -1/4)
(12/12 - 4/12 +3/12) : ( 12/12 + 4/12 - 3/12)
11/12 : 13/12 = 11/12 x 12/13 = 132/156 = 11/13