Respostas

2014-09-01T17:23:27-03:00
X+10=31 -> x=31-10 -> x=21

2x+5=15 -> 2x=10 -> x=5

x-15=30 -> x = 30+15 -> x=45

3x-10=20 -> 3x= 20+10 -> 3x=30 -> x=10

Clica em obrigado aí!
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