document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=536385>Question 536385</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Formula D=0.054^2+0.058x describes the distance in feet D that it takes a vehicle traveling x mph to stop on dry pavement.  \r<BR>\n" );
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document.write( "A. How fast can you drive if you wish to be able to stop within 65 feet?\r<BR>\n" );
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document.write( "I have it started with 0.054x^2+0.058x=65.  How do I proceed from here??  Please help! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #352299 by </B><A HREF=/tutors/aboutme.mpl?userid=lmeeks54><B>lmeeks54(111)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lmeeks54><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=lmeeks54><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=352299\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You have a quadratic equation, almost in standard form to solve.  Change:<BR>\n" );
document.write( ".054x^2 + .058x = 65 to the standard form by subtracting 65 from both sides:<BR>\n" );
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document.write( ".054x^2 + .058x - 65 = 0<BR>\n" );
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document.write( "The next step in solving quadratic equations like this is to factor the equation then solve for the X value(s) that let the equation = 0<BR>\n" );
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document.write( "Note: it will be easier to manipulate the equation by getting the coefficient for the x^2 term = 1.  Do that by dividing everything by .054:<BR>\n" );
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document.write( "x^2 + .058/.054 - 65/.054 = 0<BR>\n" );
document.write( "x^2 + 1.074x - 1203.704 = 0<BR>\n" );
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document.write( "This factors to:<BR>\n" );
document.write( "(x + 35.235) * (x - 34.162) = 0<BR>\n" );
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document.write( "x = -35.235 or x = 34.162<BR>\n" );
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document.write( "x = -35.235 mph doesn't make any sense, so reject that possible solution.  The one remaining is the correct answer.<BR>\n" );
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document.write( "x = 34.162 mph is the max speed to travel to be able to stop in 65 feet.  Note: this result is an approximation (there are actually several decimal places involved, but in practical terms of driving an automobile, they seem irrelevant). 8-)<BR>\n" );
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document.write( "Happy Thanksgiving!<BR>\n" );
document.write( "Lee </SPAN>\n" );
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