document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=170286>Question 170286</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I need help with this word problem I have tried and so has a tutor at school.<BR>\n" );
document.write( "Malikka takes a paddleboat 1km upriver against a 4km/hr current then returns downriver with the current, back to starting point. Her whole trip takes 2 hours, write a quadratic equation describing this situation. The unknown is the speed, v, that Mallika would paddle with no current present. Solve. What speed (in km/hr) would Mallika paddle by herself with no current present? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #125698 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=125698\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Malikka takes a paddleboat 1km upriver against a 4km/hr current then returns downriver with the current, back to starting point. Her whole trip takes 2 hours, write a quadratic equation describing this situation. The unknown is the speed, v, that Mallika would paddle with no current present. Solve. What speed (in km/hr) would Mallika paddle by herself with no current present?<BR>\n" );
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document.write( "Upriver DATA:<BR>\n" );
document.write( "Distance = 1 km ; rate = v-4 km/h ; time = d/r = 1/(v-4) hr.<BR>\n" );
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document.write( "Downriver DATA:<BR>\n" );
document.write( "Distance = 1 km ; rate = v+4 km/h ; time = d/r = 1/(v+4) hr.<BR>\n" );
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document.write( "EQUATION:<BR>\n" );
document.write( "time up + time down = 2 hrs<BR>\n" );
document.write( "1/(v-4) + 1/(v+4) = 2<BR>\n" );
document.write( "v+4 + v-4 = 2(v^2-16)<BR>\n" );
document.write( "v = v^2-16<BR>\n" );
document.write( "v^2 - v - 16 = 0<BR>\n" );
document.write( "v = [1 +- sqrt(1 - 4*-16)]/2<BR>\n" );
document.write( "v = [1 +- sqrt(65)]/2<BR>\n" );
document.write( "Positive solution:<BR>\n" );
document.write( "v = 4.53 km/h<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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