Réponses

2014-09-09T21:03:49+02:00
Calculer en détaillant et simplifier la fraction trouvée

A = - 5/7 + 5/7 x 7/3
A = - 5/7 + 35/21
A = - 5 x 3 / 7 x 3 - 35/21
A = - 15/21 - 35/21
A = - 50/21

B = 7/3 x (- 5) : 35
B = - 35/3 : 38
B = - 35/3 x 1/35
B = - 35/105
B = 35 x - 1 / 35 x 3
B = - 1/3

C = 3 - 5(1/5 - 1)²
C = 3 - 5 (1²/5²- 1²)
C = 3 - 5 (1/25 - 1)
C = 3 - 5 (1/25 - 1 x 25 / 1 x 25)
C = 3 - 5 (1/25 - 25/25)
C = 3 - 5 (- 24/25)
C = 3 + 120/25
C = 3 x 25 / 1 x 25 + 120/25
C = 75/25 + 120/25
C = 195/25
C = 5 x 39 / 5 x 5
C = 39/5

2014-09-09T21:20:16+02:00
A=5/7+5/7x7/3
   =5/7+35/21
   =15/21+35/21
   =50/21

B=7/3x(-5):35
  =-35/3:35/1
  =-35/3x1/35
  =-1/3

DSL le dernier je c pas bonne chance ;)