document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=562875>Question 562875</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A car travels 1500 miles at a certian speed.  If the speed had been 10 mph faster, the trip could have been made in 5 hours less time.  Find the speed </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #364724 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=364724\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+ ALIGN=MIDDLE  ALT=\"+t+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = time for the trip in hours<BR>\n" );
document.write( "at speed <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+ ALIGN=MIDDLE  ALT=\"+s+\"   DISABLED_style= \"max-width:90%; height:auto;\" > in mi/hr<BR>\n" );
document.write( "given:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1500+=s%2At+ ALIGN=MIDDLE  ALT=\"+1500+=s%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1500+=+%28+s+%2B+10+%29%2A%28+t+-+5+%29+ ALIGN=MIDDLE  ALT=\"+1500+=+%28+s+%2B+10+%29%2A%28+t+-+5+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1500+=+s%2At+%2B+10t+-+5s+-+50+ ALIGN=MIDDLE  ALT=\"+1500+=+s%2At+%2B+10t+-+5s+-+50+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Substitute (1) into (2)<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1500+=+1500+%2B+10t+-+5s+-+50+ ALIGN=MIDDLE  ALT=\"+1500+=+1500+%2B+10t+-+5s+-+50+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+10t+-+5s+-+50+=+0+ ALIGN=MIDDLE  ALT=\"+10t+-+5s+-+50+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+1500%2Fs+ ALIGN=MIDDLE  ALT=\"+t+=+1500%2Fs+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+10%2A%281500%2Fs%29+-+5s+-+50+=+0+ ALIGN=MIDDLE  ALT=\"+10%2A%281500%2Fs%29+-+5s+-+50+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+15000+-+5s%5E2+-+50s+=+0+ ALIGN=MIDDLE  ALT=\"+15000+-+5s%5E2+-+50s+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+5s%5E2+%2B+50s+-+15000+=+0+ ALIGN=MIDDLE  ALT=\"+5s%5E2+%2B+50s+-+15000+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s%5E2+%2B+10s+-+3000+=+0+ ALIGN=MIDDLE  ALT=\"+s%5E2+%2B+10s+-+3000+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Use quadratic equation<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"+s+=+%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+=+1+ ALIGN=MIDDLE  ALT=\"+a+=+1+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+10+ ALIGN=MIDDLE  ALT=\"+b+=+10+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+c+=+-3000++ ALIGN=MIDDLE  ALT=\"+c+=+-3000++\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+%28-10+%2B-+sqrt%28+10%5E2-4%2A1%2A%28-3000%29+%29%29+%2F+%282%2A1%29+ ALIGN=MIDDLE  ALT=\"+s+=+%28-10+%2B-+sqrt%28+10%5E2-4%2A1%2A%28-3000%29+%29%29+%2F+%282%2A1%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+%28-10+%2B-+sqrt%28+100+%2B+12000+%29%29+%2F+2+ ALIGN=MIDDLE  ALT=\"+s+=+%28-10+%2B-+sqrt%28+100+%2B+12000+%29%29+%2F+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+%28-10+%2B-+sqrt%28+12100+%29%29+%2F+2+ ALIGN=MIDDLE  ALT=\"+s+=+%28-10+%2B-+sqrt%28+12100+%29%29+%2F+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+%28-10+%2B+110%29+%2F+2+ ALIGN=MIDDLE  ALT=\"+s+=+%28-10+%2B+110%29+%2F+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+100%2F2+ ALIGN=MIDDLE  ALT=\"+s+=+100%2F2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+50+ ALIGN=MIDDLE  ALT=\"+s+=+50+\"   DISABLED_style= \"max-width:90%; height:auto;\" > ( I can ignore the (-) root )<BR>\n" );
document.write( "The speed is 50 mi/hr<BR>\n" );
document.write( "check answer:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1500+=s%2At+ ALIGN=MIDDLE  ALT=\"+1500+=s%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1500+=+50t+ ALIGN=MIDDLE  ALT=\"+1500+=+50t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+30+ ALIGN=MIDDLE  ALT=\"+t+=+30+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1500+=+%28+50+%2B+10+%29%2A%28+30+-+5+%29+ ALIGN=MIDDLE  ALT=\"+1500+=+%28+50+%2B+10+%29%2A%28+30+-+5+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1500+=+60%2A25+ ALIGN=MIDDLE  ALT=\"+1500+=+60%2A25+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1500+=+1500+ ALIGN=MIDDLE  ALT=\"+1500+=+1500+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );