document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=980312>Question 980312</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Felice drove her car 300km at a certain average speed. Had she travelled 10kph faster, the trip would have taken 1 hour less. Find Felice's average speed. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #601611 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52903)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=601611\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> \r<BR>\n" );
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document.write( "50 <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=km%2Fh ALIGN=MIDDLE  ALT=\"km%2Fh\"   DISABLED_style= \"max-width:90%; height:auto;\" > &nbsp;and&nbsp; 60 <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=km%2Fh ALIGN=MIDDLE  ALT=\"km%2Fh\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "I solved it momentarily without using equation &nbsp;(mentally!)\r<BR>\n" );
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document.write( "OK, &nbsp;this is a joke :)\r<BR>\n" );
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document.write( "Now let me solve it with using equations.\r<BR>\n" );
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document.write( "Let &nbsp;<B>x</B>&nbsp; be the Felice's average speed. \r<BR>\n" );
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document.write( "Then she spent &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=300%2Fx ALIGN=MIDDLE  ALT=\"300%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" >&nbsp; hours to cover &nbsp;300 km.\r<BR>\n" );
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document.write( "If she'd traveled &nbsp;10 <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=km%2Fh ALIGN=MIDDLE  ALT=\"km%2Fh\"   DISABLED_style= \"max-width:90%; height:auto;\" >&nbsp; faster, i.e. &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+%2B+10 ALIGN=MIDDLE  ALT=\"x+%2B+10\"   DISABLED_style= \"max-width:90%; height:auto;\" > <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=km%2Fh ALIGN=MIDDLE  ALT=\"km%2Fh\"   DISABLED_style= \"max-width:90%; height:auto;\" >, &nbsp;then the trip would take &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=300%2F%28x%2B10%29 ALIGN=MIDDLE  ALT=\"300%2F%28x%2B10%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, &nbsp;and it would be in &nbsp;1&nbsp; hour less than &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=300%2Fx ALIGN=MIDDLE  ALT=\"300%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" >. &nbsp;Thus you have an equation\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=300%2Fx ALIGN=MIDDLE  ALT=\"300%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" > - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=300%2F%28x%2B10%29 ALIGN=MIDDLE  ALT=\"300%2F%28x%2B10%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1.\r<BR>\n" );
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document.write( "Solve this equation simplifying it step by step:\r<BR>\n" );
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document.write( "300*(x + 10) - 300*x = x*(x +10),\r<BR>\n" );
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document.write( "300x + 3000 -300x = x^2 + 10x,\r<BR>\n" );
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document.write( "x^2 + 10x - 3000 = 0.\r<BR>\n" );
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document.write( "Next, apply the quadratic formula &nbsp;(see the lesson &nbsp;<A  rel=nofollow HREF=http://www.algebra.com/algebra/homework/quadratic/lessons/Introduction-Into-Quadratics.lesson>Introduction into Quadratic Equations</A>&nbsp; in this site) \r<BR>\n" );
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document.write( "or the &nbsp;<B>Viete's theorem</B>&nbsp; (lesson &nbsp;<A  rel=nofollow HREF=http://www.algebra.com/algebra/homework/quadratic/lessons/Solving-quadratic-equations-without-quadratic-formula.lesson>Solving quadratic equations without quadratic formula</A>). \r<BR>\n" );
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document.write( "You will get this answer: &nbsp;x = 50 <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=km%2Fh ALIGN=MIDDLE  ALT=\"km%2Fh\"   DISABLED_style= \"max-width:90%; height:auto;\" >. \r<BR>\n" );
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document.write( "Another root &nbsp;(x = -60 <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=km%2Fh ALIGN=MIDDLE  ALT=\"km%2Fh\"   DISABLED_style= \"max-width:90%; height:auto;\" >)&nbsp; is not applicable. \r<BR>\n" );
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document.write( " </SPAN>\n" );
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