document.write( "Question 618497: How do you solve this problem by substitution or elimination? (Your choice)\r
\n" ); document.write( "\n" ); document.write( "x^2+y^2+2x+2y=0
\n" ); document.write( "x^2+y^2-2x-2y=0 \n" ); document.write( "
Algebra.Com's Answer #388954 by swincher4391(1107)\"\" \"About 
You can put this solution on YOUR website!
x^2+y^2 +2x +2y =0\r
\n" ); document.write( "\n" ); document.write( "so using substitution method:\r
\n" ); document.write( "\n" ); document.write( "x^2 +y^2 = -2x -2y\r
\n" ); document.write( "\n" ); document.write( "(-2x -2y) -2x -2y = 0\r
\n" ); document.write( "\n" ); document.write( "-4x - 4y = 0\r
\n" ); document.write( "\n" ); document.write( "-4x = 4y\r
\n" ); document.write( "\n" ); document.write( "x = -y or y=-x\r
\n" ); document.write( "\n" ); document.write( "Sub y=-x in for either equation.\r
\n" ); document.write( "\n" ); document.write( "x^2 + (-x)^2 -2x + 2x = 0
\n" ); document.write( "2x^2 = 0\r
\n" ); document.write( "\n" ); document.write( "x = 0 <--------\r
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\n" ); document.write( "\n" ); document.write( "x =-y\r
\n" ); document.write( "\n" ); document.write( "0 =-y
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\n" ); document.write( "y=0 <------\r
\n" ); document.write( "\n" ); document.write( "If you want to visualize this, you have two circles that intersect at (0,0).\r
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