Respostas

2014-08-23T20:35:05-03:00
 x^{2} =81\\
x= \sqrt{81} \\
x=9


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5y= xy^{2}  \\
 y^{2} -5y=0 \\
y(y-5)=0 \\
y=0 \\
y-5=0 \\
y=5

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x+y=9+0=9
ou 
x+y= 9+5=14
2 4 2