Aidez moi pour l’exercice 1 svp :

A  = on met au deno commun ds chaque ()
(1/3+6/3)-(5/6-3/6) =
(7/3)-(2/6) =
7/3-1/3 = 6/3 = 2

B = 7/15-8/15(6/2-5/2)
   = 7/15 - 8/15 (1/2) =
   = 7/15 - 8/30
   = 7/15 - 4/15
   = 3/15 = 1/5

C = multiplication prioritaire, simplifiée avant
6/5*15/24 = 1*3/4 = 3/4
3/4 + 5/3 + 2 =
9/12 + 20/12 + 24/12 = 53/12

D =
8/21 = 2*2*2/7*3
7/18 = 7/3*3*2
3*3/2

D = 2*2*2*7*3*3/7*3*3*3*2*2
  on simplifie = 2/3