document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=961595>Question 961595</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I would like to know why the quadratic equation works? What is the proof for it? I see it online but I don't seem to understand it. Thanks </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #587558 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=587558\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Why a quadratic equation works is because it can be solved.  What you ask is uncertain.  An expression is equated to another expression, and one of the terms of either expression is a variable squared, either or both of the expressions may contain a linear term for the variable and a constant term.  That makes a quadratic equation.  Why the general form of any such equation is solvable is based on Completing the Square, in case the general form of the equation were not factorable.\r<BR>\n" );
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document.write( "You can see two lessons about that here:<BR>\n" );
document.write( "<a  rel=nofollow HREF=\"http://www.algebra.com/my/Completing-the-Square-Using-Pictures.lesson?content_action=show_dev\">What does Completing the Square mean?</a><BR>\n" );
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document.write( "<a  rel=nofollow HREF=\"http://www.algebra.com/my/Completing-the-Square-to-Solve-General-Quadratic-Equation.lesson?content_action=show_dev\">Completing the Square for Solving a Quadratic Equation</a> </SPAN>\n" );
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