How do I find the radius and center of the circle x^2 + 4x + y^2 = 5?

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- Dec 28th 2007, 12:21 PMlemon301Center and radius of a circle?
How do I find the radius and center of the circle x^2 + 4x + y^2 = 5?

- Dec 28th 2007, 12:26 PMgalactus
Complete the square.

$\displaystyle x^{2}+4x+4=(x+2)^{2}$

$\displaystyle (x+2)^{2}+(y-0)^{2}=9$

The circle is centered at (-2,0) and has radius 3. See?.