document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1009091>Question 1009091</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Given (-1,-2) (1,-4) (2,4) find the equation of the quadratic equation. \r<BR>\n" );
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document.write( "f(x)=ax^2+bx+c<BR>\n" );
document.write( "-2=a(-1)^2+b(-1)+c<BR>\n" );
document.write( "-4=a(1)^2+b(1)+c<BR>\n" );
document.write( "4=a(2)^2+b(2)+c<BR>\n" );
document.write( "-2=a-b+c<BR>\n" );
document.write( "-4=a+b+c<BR>\n" );
document.write( "4=4a+2b+c <BR>\n" );
document.write( "??????? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #624635 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39617)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=624635\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You made the correct system of equations, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%28a-b%2Bc=-2%2Ca%2Bb%2Bc=-4%2C4a%2B2b%2Bc=4%29 ALIGN=MIDDLE  ALT=\"system%28a-b%2Bc=-2%2Ca%2Bb%2Bc=-4%2C4a%2B2b%2Bc=4%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "Next, choose either row-reduction matrix operations; or elimination method, or substitution method.\r<BR>\n" );
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document.write( "Substitution method is the least advanced way, and as a start, take E1, solve for c:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a-b%2Bc=-2 ALIGN=MIDDLE  ALT=\"a-b%2Bc=-2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c=-a%2Bb-2 ALIGN=MIDDLE  ALT=\"c=-a%2Bb-2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c=b-a-2 ALIGN=MIDDLE  ALT=\"c=b-a-2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and substitute into E2 and E3:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%28a%2Bb%2Bb-a-2=-4%2C4a%2B2b%2Bb-a-2=4%29 ALIGN=MIDDLE  ALT=\"system%28a%2Bb%2Bb-a-2=-4%2C4a%2B2b%2Bb-a-2=4%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%282b-2=-4%2C3a%2B3b-2=4%29 ALIGN=MIDDLE  ALT=\"system%282b-2=-4%2C3a%2B3b-2=4%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%282b=-2%2C3a%2B3b=6%29 ALIGN=MIDDLE  ALT=\"system%282b=-2%2C3a%2B3b=6%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%28b=-1%2Ca%2Bb=2%29 ALIGN=MIDDLE  ALT=\"system%28b=-1%2Ca%2Bb=2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, which shows one of the coefficients, easily allowing for finding another by using that other's now known value...<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a=2-b ALIGN=MIDDLE  ALT=\"a=2-b\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a=2-%28-1%29 ALIGN=MIDDLE  ALT=\"a=2-%28-1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a=2%2B1 ALIGN=MIDDLE  ALT=\"a=2%2B1\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28a=3%29 ALIGN=MIDDLE  ALT=\"highlight%28a=3%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, and obviously just found as well, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28b=-1%29 ALIGN=MIDDLE  ALT=\"highlight%28b=-1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "You still want to find the value for c.  Use any equation of the system that you want. </SPAN>\n" );
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