document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=528583>Question 528583</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a car traveled 1520 miles at a certain speed. if the speed had been 19 mph faster, the trip could have been made in 4 hr less time. find the speed<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #349407 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=349407\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a car traveled 1520 miles at a certain speed.<BR>\n" );
document.write( " If the speed had been 19 mph faster, the trip could have been made in 4 hr less time. <BR>\n" );
document.write( "find the speed<BR>\n" );
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document.write( "Let s = the speed<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(s+19) = the faster speed<BR>\n" );
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document.write( "Write a time equation: time = dist/speed<BR>\n" );
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document.write( "Actual speed time - faster speed time = 4hrs<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1520%2Fs ALIGN=MIDDLE  ALT=\"1520%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1520%2F%28%28s%2B19%29%29 ALIGN=MIDDLE  ALT=\"1520%2F%28%28s%2B19%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 4<BR>\n" );
document.write( "Multiply by s(s+19) to get rid of the denominators, results:<BR>\n" );
document.write( "1520(s+19) - 1520s = 4s(s+19)<BR>\n" );
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document.write( "1520s + 28880 - 1520s = 4s^2 + 76s<BR>\n" );
document.write( "a quadratic equation<BR>\n" );
document.write( "4s^2 + 76s - 28880 = 0<BR>\n" );
document.write( "simplify, divide by 4<BR>\n" );
document.write( "s^2 + 19s - 7220 = 0<BR>\n" );
document.write( "You can use the quadratic formula here, but this will factor to<BR>\n" );
document.write( "(s+95)(s-76) = 0<BR>\n" );
document.write( "the positive solution<BR>\n" );
document.write( "s = 76 mph was his speed<BR>\n" );
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document.write( "See if that is true, find the actual times<BR>\n" );
document.write( "1520/76 = 20 hrs<BR>\n" );
document.write( "1520/95 = 16 hrs<BR>\n" );
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document.write( "differs = 4 hrs<BR>\n" );
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