Respostas

2013-08-19T16:26:05-03:00
a) 6+(-9)+1 =
6-9+1 
-3+1 = -2

b)8-(-6+10)
8-(4)
8-4
4

c)-10+(6-4)
-10+(2)
-10+2
-8

d)-5+(2-4)-(-7-1)
-5+(-2)-(-8)
-5-2+8
-7+8
1

e)2+(2+5-7)
2+(0)
2

f)(-5+3)-(5-9)+(8-1)-11
-2-(-4)+7-11
-2+4+7-11
-13+11
-2

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