document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1052699>Question 1052699</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find a quadratic model for the set of values: (-2, -20), (0, -4), (4, -20).  Show your work.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #668027 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=668027\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  Find a quadratic model for the set of values:<BR>\n" );
document.write( "Form:::::::::: ax^2 + bx + c = y<BR>\n" );
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document.write( "(-2, -20):::::a(4) - 2b + c = -20<BR>\n" );
document.write( "(0, -4)::::::: 0   +  0 + c = -4<BR>\n" );
document.write( "(4, -20):::::: a(16) +4b + c = -20<BR>\n" );
document.write( "-----------------------------------------<BR>\n" );
document.write( "Note:: c = -4<BR>\n" );
document.write( "4a - 2b -4 = -20<BR>\n" );
document.write( "16a + 4b -4 = -20<BR>\n" );
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document.write( "4a - 2b = -16<BR>\n" );
document.write( "16a + 4b = -16<BR>\n" );
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document.write( "Modify for elimination::<BR>\n" );
document.write( "8a - 4b = -32<BR>\n" );
document.write( "16a + 4b = -16<BR>\n" );
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document.write( "24a = -48<BR>\n" );
document.write( "a = -2<BR>\n" );
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document.write( "Solve for \"b\"::<BR>\n" );
document.write( "4a - 2b = -16<BR>\n" );
document.write( "4(-2) - 2b = -16<BR>\n" );
document.write( "-8 - 2b = -16<BR>\n" );
document.write( "2b = 8<BR>\n" );
document.write( "b = 4<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "  </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );