Réponses

2013-11-10T16:12:06+01:00
B + C = (-6/5)+2/3
           -18/15+10/15
         = -8/15
A - D = 15/7-(-4/3)
        =45/21-(-28/21)
          = 45/21+28+21=73/21
B x A=-6/5 x 15/7
         =-90/35 ou -18/7
C + D= 2/3+(-4/3)
         =2/3-4/3=-2/3