document.write( "Question 715117: Find the center(h,k) and the radius(r) of the circle and use them to graph it. Find any intercepts.
\n" ); document.write( " 5x^2+40x+5y^2=0 \n" ); document.write( "

Algebra.Com's Answer #439216 by Edwin McCravy(20060) $\"\"$ $\"About$

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document.write( " 5x² + 40x + 5y² = 0\r\n" );
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document.write( "Divide every term by 5\r\n" );
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document.write( "    x² + 8x + y² = 0\r\n" );
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document.write( "Complete the square with the first two terms:\r\n" );
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document.write( "1. Multiply 8 times  getting 4\r\n" );
document.write( "2. Square 4 getting 16\r\n" );
document.write( "3. Add 16 to both sides after the term in y\r\n" );
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document.write( "    x² + 8x + 16 + y² = 0 + 16\r\n" );
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document.write( "Factor the first three terms\r\n" );
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document.write( "      (x+4)(x+4) + y² = 16\r\n" );
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document.write( "          (x+4)² + y² = 16     \r\n" );
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document.write( "Since there is no y-term, we complete the square on y²\r\n" );
document.write( "simply by writing it as (y-0)².  Write 16 as 4²:\r\n" );
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document.write( "      (x+4)² + (y-0)² = 4²\r\n" );
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document.write( "Compare that to the standard form equation for a circle\r\n" );
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document.write( "      (x-h)² + (y-k)² = r²\r\n" );
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document.write( "The center (h,k) = (-4,0).  The radius r=4\r\n" );
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document.write( "Edwin

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