Réponses

2013-12-14T14:08:47+01:00
A = 2/5 - 4/3 + 7/2
= 6/15 - 20/15 + 7/2
= -14/15 + 7/2
= -28/30 + 105/30
= 77/30

B = 2/3 - 5/3 x 3/2
= 2/3 - 15/6
= 4/6 - 15/6
= -11/6

C = ( -7/4 + 1/2 ) : ( 2/7 + 1/4 )
= ( -7/4 + 2/4 ) : ( 8/28 + 7/28 )
= -5/4 : 15/28
= -5/4 x 28/15
= -140/60
= -7/3