Réponses

2014-02-24T13:45:12+01:00
A=1/5+5/7*7/25
=1/5+5/25
=1/5+1/5
=2/5

B=(3/5+7/15)*3/12
=(9/15+7/15)*1/4
=16/15*1/4
=4/15

C=4/5*15/3+28/6*6/7
=4/5*5+28/7
=4+4
=8

D=(5/2+3/4)*(7/2-5/6)
=(10/4+3/4)*(21/6-5/6)
=13/4*16/6
=13/4*8/3
=13*2/3
=26/3

E=2/9*(5/3+5/9+14/12)
=2/9*(15/9+5/9+7/6)
=2/9*(20/9+7/6)
=2/9*(40/18+21/18)
=2/9*61/18
=1/9*61/9
=61/81

* est le signe de la multiplication