document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=934762>Question 934762</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Using one engine of a ferry boat, it takes 6 h longer to cross a channel than it does using a second engine alone. with both engines operating, the ferryboat can make the crossing in 4 h. how long would it take each engine, working alone, to power the ferry boat across the channel? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #567777 by </B><A HREF=/tutors/aboutme.mpl?userid=TimothyLamb><B>TimothyLamb(4379)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=TimothyLamb><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=TimothyLamb><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=567777\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> x = time for engine A alone<BR>\n" );
document.write( "y = time for engine B alone<BR>\n" );
document.write( "---<BR>\n" );
document.write( "y = x + 6<BR>\n" );
document.write( "---<BR>\n" );
document.write( "r = w/t<BR>\n" );
document.write( "rates are additive:<BR>\n" );
document.write( "1/x + 1/y = 1/4<BR>\n" );
document.write( "---<BR>\n" );
document.write( "1/x + 1/y = 1/4<BR>\n" );
document.write( "1/x + 1/(x + 6) = 1/4<BR>\n" );
document.write( "1(x + 6)/x(x + 6) + 1x/x(x + 6) = 1/4<BR>\n" );
document.write( "1(x + 6) + 1x = (1/4)x(x + 6)<BR>\n" );
document.write( "x + 6 + x = (1/4)xx + (6/4)x<BR>\n" );
document.write( "(1/4)xx + (6/4)x - 2x - 6 = 0<BR>\n" );
document.write( "(1/4)xx + (6/4)x - (8/4)x - 6 = 0<BR>\n" );
document.write( "(1/4)xx - (2/4)x - 6 = 0<BR>\n" );
document.write( "4*( (1/4)xx - (2/4)x - 6 = 0 )<BR>\n" );
document.write( "xx - 2x - 24 = 0<BR>\n" );
document.write( "---<BR>\n" );
document.write( "the above quadratic equation is in standard form, with a=1, b=-2 and c=-24<BR>\n" );
document.write( "---<BR>\n" );
document.write( "to solve the quadratic equation, by using the quadratic formula, copy and paste this:<BR>\n" );
document.write( "1 -2 -24<BR>\n" );
document.write( "into this solver: https://sooeet.com/math/quadratic-equation-solver.php<BR>\n" );
document.write( "---<BR>\n" );
document.write( "the quadratic has two real roots at:<BR>\n" );
document.write( "---<BR>\n" );
document.write( "x = 6<BR>\n" );
document.write( "x = -4<BR>\n" );
document.write( "---<BR>\n" );
document.write( "the negative root doesn't fit the problem statement, so use the positive root:<BR>\n" );
document.write( "---<BR>\n" );
document.write( "x = 6<BR>\n" );
document.write( "y = x + 6<BR>\n" );
document.write( "y = 6 + 6<BR>\n" );
document.write( "y = 12<BR>\n" );
document.write( "---<BR>\n" );
document.write( "answer:<BR>\n" );
document.write( "x = time for engine A alone = 6 hours<BR>\n" );
document.write( "y = time for engine B alone = 12 hours<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Free algebra tutoring live chat:<BR>\n" );
document.write( "https://sooeet.com/chat.php?gn=algebra<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Solve and graph linear equations:<BR>\n" );
document.write( "https://sooeet.com/math/linear-equation-solver.php<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Solve quadratic equations with quadratic formula:<BR>\n" );
document.write( "https://sooeet.com/math/quadratic-formula-solver.php<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Solve systems of linear equations up to 6-equations 6-variables:<BR>\n" );
document.write( "https://sooeet.com/math/system-of-linear-equations-solver.php<BR>\n" );
document.write( "--- </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );