document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=309433>Question 309433</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I think I got the equation right to solve this word problem:  You drive to California.  On the way, you averaged 10 miles per hour less, and the drive took you 5 extra hours.  What was your average speed on thw\e way to California?\r<BR>\n" );
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document.write( "This is the formula I used but not sure how to solve it:<BR>\n" );
document.write( "1500=(R-10)(T+5) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #221308 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=221308\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  You drive to California. On the way, you averaged 10 miles per hour less, and the drive took you 5 extra hours. What was your average speed on thw\e way to California?<BR>\n" );
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document.write( "I would do it this way:<BR>\n" );
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document.write( "Let r = speed on the way to Calif<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(r+10) = speed on the return trip<BR>\n" );
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document.write( "Let 1500 mi = one way distance<BR>\n" );
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document.write( "Write a time equation; time = dist/speed<BR>\n" );
document.write( "to Calif time - return time = 5 hrs<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1500%2Fr ALIGN=MIDDLE  ALT=\"1500%2Fr\"   DISABLED_style= \"max-width:90%; height:auto;\" > - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1500%2F%28r%2B10%29 ALIGN=MIDDLE  ALT=\"1500%2F%28r%2B10%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 5 hrs<BR>\n" );
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document.write( "multiply by r(r+10), results:<BR>\n" );
document.write( "1500(r+10) - 1500r = 5r(r+10)<BR>\n" );
document.write( "1500r + 15000 - 1500r = 5r^2 + 50r<BR>\n" );
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document.write( "Combine on the right<BR>\n" );
document.write( "0 = 5r^2 + 50r - 15000<BR>\n" );
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document.write( "simplify, divide by 5, results<BR>\n" );
document.write( "r^2 + 10r - 3000 = 0<BR>\n" );
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document.write( "Factors to<BR>\n" );
document.write( "(r+60)(r-50) = 0<BR>\n" );
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document.write( "the positive solution is what we want here<BR>\n" );
document.write( "r = 50 mph is the speed to Calif<BR>\n" );
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document.write( "Check solutions by finding the times: (return trip speed = 60 mph)<BR>\n" );
document.write( "1500/50 = 30 hrs<BR>\n" );
document.write( "1500/60 = 25 hrs<BR>\n" );
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document.write( "time dif: 5 hrs\r<BR>\n" );
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document.write( " </SPAN>\n" );
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