Réponses

2014-03-24T23:38:57+01:00
A)  9 - 17 = - 8
b) -2.7 - 9.12 = - 11.82
c) -5.4 - (-3.9) = -5,4 + 3.9 = - 1,5
d) -3 + (-23) + 7 + (-5.2) +3
 = -3 -23 + 7 -5.2 + 3
= -3 - 23 -5.2 + 7 + 3
= - 31.2 + 10
= - 21.2
2014-03-24T23:39:34+01:00
A)  -8
b)  -11.82
c)  -5.4 + 3.9= -1.5
d)  -3 -23 + 7 -5.2 +3= -26 + 10 -5.2 =  - 21.2

Voili voilou