Respostas

2013-11-17T09:22:43-02:00
A) 4-2-3=0
-9= x
x =-9
b)9-3-(-1)=0
-7=x
x=-7
c) 38-8-3-(-4)=0
2x=31
x=31/2
x=15,5
d)7-3-2-1=0
1=x+1
x=1-1
x= 0

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