SOLUTION: Identify the conic section and write the standard form of the equation {{{x^2+y^2+8x-4y=-11}}}

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Question 79149: Identify the conic section and write the standard form of the equation x%5E2%2By%5E2%2B8x-4y=-11
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
x and y both squared with the same coefficient on the square terms means a circle

the rest of the terms give the location of the center and the radius ... the general equation is %28x-h%29%5E2%2B%28y-k%29%5E2=r%5E2

complete the squares for x and y by taking 1/2 of the coefficient of the first order term, square it and add it

... so %28x%2B4%29%5E2%2B%28y-2%29%5E2=9

this is a circle centered at (-4,2) with a radius of 3