Réponses

2013-11-24T18:20:21+01:00
A= 7/10-2/5×15/7
=7/10-30/35
=7/10-6/7
=49/70-60/70
=-11/70

B= 1+5/3:-7/9
=(3/3+5/3)x(-9/7)
=8/3x(-9/7)
=-72/21
=-24/7