Réponses

  • Utilisateur Brainly
2014-03-19T19:20:20+01:00
12/15=(3*4)/(3*5)=4/5 
20/80=(20*1)/(20*4)=1/4
15/21=(3*5)/(3*7)=5/7
40/25=(5*8)/(5*5)=8/5
42/60=(6*7)/(6*10)=7/10

  • Utilisateur Brainly
2014-03-19T19:31:49+01:00
Simplifications:

12/15 = (3x4) / (3x5) = 4/5

20/80 = 20 / (4x20) = 1/4

15/21 = (3x5) / (3x7) = 5/7

40/25 = (8x5) / (5x5) = 8/5

42/60 = (6x7) / (6x10) = 7/10

Voilà ! J'espère t'avoir aidé(e) ! :)