Respostas

2013-12-15T17:27:03-02:00
X²+y²-4x+6y+4=0
(x²-4x)+(y²+6y)=-4
(x²-4x+4)+(y²+6y+9)=-4+4+9
(x-2)²+(y+3)²=9
C={(-3;2)}
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