document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=841180>Question 841180</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A group of students held a car wash to raise money. They<BR>\n" );
document.write( "charged $9 for each car and $12 for each van or SUV. Two teams worked<BR>\n" );
document.write( "continuously, one washing cars and the other washing vans and SUVs.<BR>\n" );
document.write( "The team washing cars required 25% less time per vehicle than the other<BR>\n" );
document.write( "team. Each team washed vehicles for 4 hours. The two teams together<BR>\n" );
document.write( "raised a total of $720. How long, on average, did each team take to wash<BR>\n" );
document.write( "a vehicle? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #506696 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=506696\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a+ ALIGN=MIDDLE  ALT=\"+a+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the number of cars the <BR>\n" );
document.write( "car washing team washed in 4 hrs<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+ ALIGN=MIDDLE  ALT=\"+b+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the number of vans and<BR>\n" );
document.write( "SUVs the other team washed in 4 hrs<BR>\n" );
document.write( "If I increase the ( time/vehicle ) for the car<BR>\n" );
document.write( "washers by 25%, that equals the <BR>\n" );
document.write( "( time/vehicle ) for the van/SUV washers <BR>\n" );
document.write( "---------------------------------<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+4%2Fa+%2B+.25%2A%28+4%2Fa+%29+=+4%2Fb+ ALIGN=MIDDLE  ALT=\"+4%2Fa+%2B+.25%2A%28+4%2Fa+%29+=+4%2Fb+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+9a+%2B+12b+=+720+ ALIGN=MIDDLE  ALT=\"+9a+%2B+12b+=+720+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "--------------------------<BR>\n" );
document.write( "Multiply both sides of (1) by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a%2Ab+ ALIGN=MIDDLE  ALT=\"+a%2Ab+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+4b+%2B+b+=+4a+ ALIGN=MIDDLE  ALT=\"+4b+%2B+b+=+4a+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+5b+=+4a+ ALIGN=MIDDLE  ALT=\"+5b+=+4a+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+%284%2F5%29%2Aa+ ALIGN=MIDDLE  ALT=\"+b+=+%284%2F5%29%2Aa+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------------<BR>\n" );
document.write( "Substitute (1) into (2)<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+9a+%2B+12b+=+720+ ALIGN=MIDDLE  ALT=\"+9a+%2B+12b+=+720+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+9a+%2B+12%2A%284%2F5%29%2Aa+=+720+ ALIGN=MIDDLE  ALT=\"+9a+%2B+12%2A%284%2F5%29%2Aa+=+720+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+9a+%2B+%2848%2F5%29%2Aa+=+720+ ALIGN=MIDDLE  ALT=\"+9a+%2B+%2848%2F5%29%2Aa+=+720+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Multiply both sides by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+5+ ALIGN=MIDDLE  ALT=\"+5+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+45a+%2B+48a+=+3600+ ALIGN=MIDDLE  ALT=\"+45a+%2B+48a+=+3600+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+93a+=+3600+ ALIGN=MIDDLE  ALT=\"+93a+=+3600+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a+=+38.71+ ALIGN=MIDDLE  ALT=\"+a+=+38.71+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+%284%2F5%29%2Aa+ ALIGN=MIDDLE  ALT=\"+b+=+%284%2F5%29%2Aa+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+%284%2F5%29%2A38.71+ ALIGN=MIDDLE  ALT=\"+b+=+%284%2F5%29%2A38.71+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+31+ ALIGN=MIDDLE  ALT=\"+b+=+31+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------------<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a%2F4+=+39%2F4+ ALIGN=MIDDLE  ALT=\"+a%2F4+=+39%2F4+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a%2F4+=+9.75+ ALIGN=MIDDLE  ALT=\"+a%2F4+=+9.75+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b%2F4+=+31%2F4+ ALIGN=MIDDLE  ALT=\"+b%2F4+=+31%2F4+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b%2F4+=+7.75+ ALIGN=MIDDLE  ALT=\"+b%2F4+=+7.75+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-----------------<BR>\n" );
document.write( "The car-washers average 9.75 vehicles/hr<BR>\n" );
document.write( "The van/SUV washers average 7.75 vehicles/hr<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+9%2A39+%2B+12%2A31+=+720+ ALIGN=MIDDLE  ALT=\"+9%2A39+%2B+12%2A31+=+720+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+351+%2B+372++=+720+ ALIGN=MIDDLE  ALT=\"+351+%2B+372++=+720+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+723+=+720+ ALIGN=MIDDLE  ALT=\"+723+=+720+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "close enough<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+%284%2F5%29%2Aa+ ALIGN=MIDDLE  ALT=\"+b+=+%284%2F5%29%2Aa+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+31+=+.8%2A39+ ALIGN=MIDDLE  ALT=\"+31+=+.8%2A39+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+31+=+31.2+ ALIGN=MIDDLE  ALT=\"+31+=+31.2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK<BR>\n" );
document.write( "You might want a 2nd opinion on this<BR>\n" );
document.write( "the numbers seem a little strange\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );