Réponses

2013-11-04T20:26:05+01:00
-2)+(-5-[(-12+(-1)]
=-2+(-5-(-12-1))
=-2+(-5-(-13))
=-2+(-5+13)
=-2-5+13
=-7+13
=6                                    

c) 1-2)+(3-2)-(6-7)-(8-7)
=1-2+3-2-6+7-8+7    
=0         

d) -4+(-5)+[5-(-1)  
=-4-5+(5+1)
=-4-5+6
=-9+6
=-3