document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=967245>Question 967245</A>: <I><SPAN STYLE=\"word-break: break-all;\"> After a certain number of days, a bicycle factory had produced 400 bicycles. In the next 3days, the factory produced 37 bicycles and lowered its average number of bicycles produced per day by 1. What was its final average? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #591238 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=591238\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> After a certain number of days, a bicycle factory had produced 400 bicycles.<BR>\n" );
document.write( " In the next 3days, the factory produced 37 bicycles and lowered its average number of bicycles produced per day by 1.<BR>\n" );
document.write( " What was its final average?<BR>\n" );
document.write( ":<BR>\n" );
document.write( "let d = the \"certain number of days<BR>\n" );
document.write( "then<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=400%2Fd ALIGN=MIDDLE  ALT=\"400%2Fd\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the original daily average<BR>\n" );
document.write( ":<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=437%2F%28%28d%2B3%29%29 ALIGN=MIDDLE  ALT=\"437%2F%28%28d%2B3%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = final average<BR>\n" );
document.write( ":<BR>\n" );
document.write( "original av - final av = 1<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=400%2Fd ALIGN=MIDDLE  ALT=\"400%2Fd\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=437%2F%28%28d%2B3%29%29 ALIGN=MIDDLE  ALT=\"437%2F%28%28d%2B3%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1<BR>\n" );
document.write( "multiply equation by d(d+3), cancel the denominators and we have<BR>\n" );
document.write( "400(d+3) - 437d = d(d+3)<BR>\n" );
document.write( "400d + 1200 - 437d = d^2 + 3d<BR>\n" );
document.write( "1200 - 37d = d^2 + 3d<BR>\n" );
document.write( "Arrange to form a quadratic equation on the right<BR>\n" );
document.write( "0 = d^2 + 3d + 37d - 1200<BR>\n" );
document.write( "d^2 + 40d - 1200 = 0<BR>\n" );
document.write( "Factors to<BR>\n" );
document.write( "(d+60)(d-20) = 0<BR>\n" );
document.write( "d = 20 the certain number of days<BR>\n" );
document.write( "then<BR>\n" );
document.write( "23 days for the final average<BR>\n" );
document.write( "therefore<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=437%2F23 ALIGN=MIDDLE  ALT=\"437%2F23\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 19 bikes a day is the final average<BR>\n" );
document.write( ":<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Confirm this by finding the original average: 400/20 = 20 bikes a day<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );