document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=138443>Question 138443</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the center and radius by completing the square.<BR>\n" );
document.write( "x^2+y^2+10x+7=0 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #101094 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=101094\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Step 1: Move the constant term to the left side:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2%2By%5E2%2B10x=-7 ALIGN=MIDDLE  ALT=\"x%5E2%2By%5E2%2B10x=-7\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Step 2: Put the x terms together and the y terms together:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2%2B10x%2By%5E2=-7 ALIGN=MIDDLE  ALT=\"x%5E2%2B10x%2By%5E2=-7\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Step 3: Complete the square on the x variable.  Divide the coefficient of the 1st degree x term by 2 and square the result:  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%2810%2F2%29%5E2=5%5E2=25 ALIGN=MIDDLE  ALT=\"%2810%2F2%29%5E2=5%5E2=25\"   DISABLED_style= \"max-width:90%; height:auto;\" >.  Add this value to both sides of the equation.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2%2B10x%2B25%2By%5E2=-7%2B25 ALIGN=MIDDLE  ALT=\"x%5E2%2B10x%2B25%2By%5E2=-7%2B25\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2%2B10x%2B25%2By%5E2=18 ALIGN=MIDDLE  ALT=\"x%5E2%2B10x%2B25%2By%5E2=18\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Step 4: Complete the square on the y variable:  Since there is no 1st degree y term, there is nothing to do.\r<BR>\n" );
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document.write( "Step 5: Factor the perfect squares:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x%2B5%29%5E2%2By%5E2=18 ALIGN=MIDDLE  ALT=\"%28x%2B5%29%5E2%2By%5E2=18\"   DISABLED_style= \"max-width:90%; height:auto;\" >, but re-write it thus so that the coordinates of the center are obvious:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x%2B5%29%5E2%2B%28y-0%29%5E2=18 ALIGN=MIDDLE  ALT=\"%28x%2B5%29%5E2%2B%28y-0%29%5E2=18\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Since we know that the equation of a circle with center at (h,k) and radius r is:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x-h%29%5E2%2B%28y-k%29%5E2=r%5E2 ALIGN=MIDDLE  ALT=\"%28x-h%29%5E2%2B%28y-k%29%5E2=r%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > we can see that the center of your circle is at (-5,0) and the radius is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%2818%29=3sqrt%282%29 ALIGN=MIDDLE  ALT=\"sqrt%2818%29=3sqrt%282%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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