Réponses

2014-09-18T07:51:12+02:00
23)
A = 4/3 x 9/5 - 3/2
A = 36/15 - 3/2
A = 36 x 2 / 15 x 2 - 3 x 15 / 2 x 15
A = 72/30 - 45/30
A = 27/30
A = 3 x 9 / 3 x 10
A = 9/10

B = 4/3 (9/5 - 3/2)
B = 4/3 (9 x 2 / 5 x 2 - 3 x 5 / 2 x 5)
B = 4/3 (18/10 - 15/10)
B = 4/3 (3/10)
B = 12/30
B = 3 x 4 / 3 x 10
B = 4/10

24)
A = (2/5 + 1/3) : 11/3
A = (2 x 3 / 5 x 3 + 1 x 5 / 3 x 5) : 11/3
A = (6/15 + 5/15) : 11/3
A = 11/15 : 11/3
A = 11/15 x 3/11
A = 33/165
A = 33 x 1 / 33 x 5
A = 1/5

B = 22/15 : 4/9 - 5/2
B = 22/15 x 9/4 - 5/2
B = 198/60 - 5/2
B = 198/60 + 5 x 30 / 2 x 30
B = 198/60 + 150/60
B = 348/60
B = 12 x 29 / 12 x 5
B = 29/5

25)
A = 5/2 - 7/4
          3/8
A = 5 x 2 / 2 x 2 - 7/4
               3/8
A = 10/4 - 7/4
           3/8
A = 3/4 : 3/8
A = 3/4 x 8/3
A = 24/12
A = 12 x 2 / 12 x 1
A = 2/1
A = 2

B = 5/4 - 3
     2 x 11/6
B = 5/4 - 3 x 4 / 1 x 4
               22/6
B = 5/4 - 12/4
         22/6
B = - 7/4 ; 22/6
B = - 7/4 x 6/22
B = - 42/88
B = 2 x - 21 / 2 x 44
B = - 21/44