Respostas

2014-06-01T14:14:52-03:00
2x=5
x= \frac{5}{2}
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 \frac{x}{5} +1=21 \\  \\ 
 \frac{x}{5}=21-1 \\  \\ 
 \frac{x}{5}= 20  \\  \\ 
x=20.5 \\  \\ 
x=100
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 \frac{x}{2} -5=10 \\  \\ 
 \frac{x}{2}=10+5 \\  \\ 
 \frac{x}{2}=15 \\  \\ 
x=15.2 \\  \\ 
x=30
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2014-06-01T14:22:08-03:00
X/5+1=21
x=5.21
x=105

x/2-5=10
x-5=2.10
x-5=20
x=25

Acho que é assim.
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