Respuestas

2013-10-08T14:45:31+02:00
(+5-3)-(3+7-2-4)
= (2) - (4)
= -2


8-(4+3-1)+(-1-5-7)
= 8 - (6) + (-13)
= 8 - 6 - 13
= -11
2013-10-08T16:10:34+02:00
(+5-3)- (3+7-2-4)=6
=(2 positivo ) =(4 positivo)
signos yguales se suman = 6