document.write( "Question 378272: Complete the square and write the equation in standard form. Then give the center and radius of the circle. Graph on graph paper.\r
\n" ); document.write( "\n" ); document.write( "x^2 + y^2 + 2x - 4y - 31 = 0\r
\n" ); document.write( "\n" ); document.write( "(x-h)^2 + (y-k)^2 = r^2 Standard form
\n" ); document.write( " Center
\n" ); document.write( " Radius
\n" ); document.write( "Step by step sequence. Thanks.
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Algebra.Com's Answer #268789 by Fombitz(32388)\"\" \"About 
You can put this solution on YOUR website!
Complete the square in x and y.
\n" ); document.write( "\"x%5E2+%2B+y%5E2+%2B+2x+-+4y+-+31+=+0+\"
\n" ); document.write( "\"%28x%5E2%2B2x%29%2B%28y%5E2-4y%29-31=0\"
\n" ); document.write( "\"%28x%5E2%2B2x%2B1%29%2B%28y%5E2-4y%2B4%29-31=1%2B4\"
\n" ); document.write( "\"%28x%2B1%29%5E2%2B%28y-2%29%5E2=36\"
\n" ); document.write( "\"%28x%2B1%29%5E2%2B%28y-2%29%5E2=6%5E2\"
\n" ); document.write( "The general equation for a circle centered at (\"h\",\"k\") with a radius \"R\" is:
\n" ); document.write( "\"%28x-h%29%5E2%2B%28y-k%29%5E2=R%5E2\"
\n" ); document.write( "Comparing,
\n" ); document.write( "Radius:\"R=6\"
\n" ); document.write( "Center:(\"h\",\"k\")=(\"-1\",\"2\")
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