document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=767354>Question 767354</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Sir/Madam,<BR>\n" );
document.write( "     A pleasant day! Please help me understand how to solve this problem.  Find the value of k so that the equation is:  <BR>\n" );
document.write( "2x^2+kx-15=0, has one root of 3<BR>\n" );
document.write( "Thank you very much for your help! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #467568 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=467568\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2x%5E2+%2B+k%2Ax+-+15+=+0+ ALIGN=MIDDLE  ALT=\"+2x%5E2+%2B+k%2Ax+-+15+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "I would use the quadratic formula:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"+x+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%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+ ALIGN=MIDDLE  ALT=\"+a+=+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+k+ ALIGN=MIDDLE  ALT=\"+b+=+k+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+c+=+-15+ ALIGN=MIDDLE  ALT=\"+c+=+-15+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28-k+%2B-+sqrt%28+k%5E2+-+4%2A2%2A%28-15%29+%29%29+%2F+%282%2A2%29+ ALIGN=MIDDLE  ALT=\"+x+=+%28-k+%2B-+sqrt%28+k%5E2+-+4%2A2%2A%28-15%29+%29%29+%2F+%282%2A2%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28-k+%2B-+sqrt%28+k%5E2+%2B+120+%29%29+%2F+4+ ALIGN=MIDDLE  ALT=\"+x+=+%28-k+%2B-+sqrt%28+k%5E2+%2B+120+%29%29+%2F+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "---------------------------------<BR>\n" );
document.write( "If one of the roots is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+3+ ALIGN=MIDDLE  ALT=\"+3+\"   DISABLED_style= \"max-width:90%; height:auto;\" >, I can say:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+3+=+%28-k+%2B+sqrt%28+k%5E2+%2B+120+%29%29+%2F+4+ ALIGN=MIDDLE  ALT=\"+3+=+%28-k+%2B+sqrt%28+k%5E2+%2B+120+%29%29+%2F+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+-k+%2B+sqrt%28+k%5E2+%2B+120+%29+=+12+ ALIGN=MIDDLE  ALT=\"+-k+%2B+sqrt%28+k%5E2+%2B+120+%29+=+12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+sqrt%28+k%5E2+%2B+120+%29+=+k+%2B+12+ ALIGN=MIDDLE  ALT=\"+sqrt%28+k%5E2+%2B+120+%29+=+k+%2B+12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Square both sides<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+k%5E2+%2B+120+=+k%5E2+%2B+24k+%2B+144+ ALIGN=MIDDLE  ALT=\"+k%5E2+%2B+120+=+k%5E2+%2B+24k+%2B+144+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+24k+=+-24+ ALIGN=MIDDLE  ALT=\"+24k+=+-24+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+k+=+-1+ ALIGN=MIDDLE  ALT=\"+k+=+-1+\"   DISABLED_style= \"max-width:90%; height:auto;\" > answer<BR>\n" );
document.write( "------------<BR>\n" );
document.write( "I'll see if this works<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28-%28-1%29+%2B-+sqrt%28+%28-1%29%5E2+%2B+120+%29%29+%2F+4+ ALIGN=MIDDLE  ALT=\"+x+=+%28-%28-1%29+%2B-+sqrt%28+%28-1%29%5E2+%2B+120+%29%29+%2F+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28+1+%2B-+sqrt%28+1+%2B+120+%29%29+%2F+4+ ALIGN=MIDDLE  ALT=\"+x+=+%28+1+%2B-+sqrt%28+1+%2B+120+%29%29+%2F+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28+1+%2B+11+%29+%2F+4+ ALIGN=MIDDLE  ALT=\"+x+=+%28+1+%2B+11+%29+%2F+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+12%2F4+ ALIGN=MIDDLE  ALT=\"+x+=+12%2F4+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+3+ ALIGN=MIDDLE  ALT=\"+x+=+3+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and, also.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28+1+-+sqrt%28+1+%2B+120+%29%29+%2F+4+ ALIGN=MIDDLE  ALT=\"+x+=+%28+1+-+sqrt%28+1+%2B+120+%29%29+%2F+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28+1+-+11+%29+%2F+4+ ALIGN=MIDDLE  ALT=\"+x+=+%28+1+-+11+%29+%2F+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+-10%2F4+ ALIGN=MIDDLE  ALT=\"+x+=+-10%2F4+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+-5%2F2+ ALIGN=MIDDLE  ALT=\"+x+=+-5%2F2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2x+=+-5+ ALIGN=MIDDLE  ALT=\"+2x+=+-5+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+x-3+%29%2A%28+2x+%2B+5+%29+=+0+ ALIGN=MIDDLE  ALT=\"+%28+x-3+%29%2A%28+2x+%2B+5+%29+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2x%5E2+%2B+%28-1%29%2Ax+-+15+=+0+ ALIGN=MIDDLE  ALT=\"+2x%5E2+%2B+%28-1%29%2Ax+-+15+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK <BR>\n" );
document.write( " <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );