document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=136647>Question 136647</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0395977223/algebrahomeworkh>Algebra Structure and Method</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> Jacqui commutes 30 mi to her job each day.  She finds that if she drives 10 mi/h faster, it takes her 6 min less to get to work.  Find her new speed. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #100068 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=100068\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Jacqui commutes 30 mi to her job each day. She finds that if she drives 10 mi/h faster, it takes her 6 min less to get to work. Find her new speed<BR>\n" );
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document.write( "Let s = new speed<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(s-10) = original speed<BR>\n" );
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document.write( "Convert 6 min to hrs: 6/60 = .1 hrs<BR>\n" );
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document.write( "Write a time equation: Time = dist/speed<BR>\n" );
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document.write( "Fast trip + 6 min = slow trip<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30%2Fs ALIGN=MIDDLE  ALT=\"30%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > + .1 = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30%2F%28%28s-10%29%29 ALIGN=MIDDLE  ALT=\"30%2F%28%28s-10%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Multiply equation by s(s-10) to get rid of the denominators:<BR>\n" );
document.write( "s(s-10)*<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30%2Fs ALIGN=MIDDLE  ALT=\"30%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > + .1(s(s-10) = s(s-10)*<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30%2F%28%28s-10%29%29 ALIGN=MIDDLE  ALT=\"30%2F%28%28s-10%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Results<BR>\n" );
document.write( "30(s-10) + .1s^2 - 1s = 30s<BR>\n" );
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document.write( "30s - 300 + .1s^2 - s - 30s = 0<BR>\n" );
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document.write( ".1s^2 - s - 300 = 0; a quadratic equation<BR>\n" );
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document.write( "s^2 - 10s - 3000 = 0; mult by 10 to get rid of the decimal<BR>\n" );
document.write( "Factors to:<BR>\n" );
document.write( "(s-60)(s+50) = 0<BR>\n" );
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document.write( "S = 60 mph is the new speed<BR>\n" );
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document.write( "Check solution by finding the times of each trip:<BR>\n" );
document.write( "30/50 = .6 hrs or 36 min<BR>\n" );
document.write( "30/60 = .5 hrs or 30 min<BR>\n" );
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document.write( "difference time = 6 min\r<BR>\n" );
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document.write( " =  </SPAN>\n" );
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