document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=669514>Question 669514</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Given that the quadratic equation\r<BR>\n" );
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document.write( "(1-k)x^2+8x+1-k=0\r<BR>\n" );
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document.write( "has equal roots, find the possible values of k. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #416414 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=416414\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Given that the quadratic equation <BR>\n" );
document.write( "(1-k)x^2+8x+1-k=0 <BR>\n" );
document.write( "has equal roots, find the possible values of k.<BR>\n" );
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document.write( "If roots are equal, b^2-4ac = 0<BR>\n" );
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document.write( "a = 1-k<BR>\n" );
document.write( "b = 8<BR>\n" );
document.write( "c = 1-k<BR>\n" );
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document.write( "b^2-4ac = 64 - 4(1-k)^2 = 64-4(1-2k+k^2) = -4k^2+8k+60<BR>\n" );
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document.write( "Solve: <BR>\n" );
document.write( "-4k^2+8k+60 = 0<BR>\n" );
document.write( "k^2 -2k - 15 = 0<BR>\n" );
document.write( "(k-5)(k+3) = 0<BR>\n" );
document.write( "Possible value of \"k\":<BR>\n" );
document.write( "k = 5 or k = -3<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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document.write( " </SPAN>\n" );
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