Réponses

2014-02-17T16:16:41+01:00
A=(+12)+(-5)-(+4)
12-5-4
3

B=(-7)+(+6)-(-9)
-7+6+9
8

C=(+5)-(+8)-(2)
5-8-2
-5
2014-02-17T16:21:08+01:00
A= +12 + (-5) - (+4)
= +12 - 5 - 4
= 7 - 4
= 3

B= (-7) + 6 - (-9)
= -7 + 6 + 9
= -1 + 9
= 8

C= +5 - (+8) -2
= +5 - 8 - 2
= -3 - 2
= -5