document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=185589>Question 185589</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hello, I'm trying to help my son with his math homework but it's been 30 years since I had to do math and I can't remember enough to help him.\r<BR>\n" );
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document.write( "One example of the type of questions he has would be:<BR>\n" );
document.write( "tennis consumes 25 calories a minute<BR>\n" );
document.write( "cycling consumes 35 calories a minute<BR>\n" );
document.write( "The player plays both sports for a total of 50 minutes consuming 1450 calories. How long did he play tennis?\r<BR>\n" );
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document.write( "I've been trying to come up with something like 25x + 35y = 1450 but I can't go from there. \r<BR>\n" );
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document.write( "I'd be grateful if you could quickly give me some idea how to do the above.\r<BR>\n" );
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document.write( "Thanks<BR>\n" );
document.write( "John Mullany </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #139216 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=139216\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> tennis consumes 25 calories a minute<BR>\n" );
document.write( "cycling consumes 35 calories a minute<BR>\n" );
document.write( "The player plays both sports for a total of 50 minutes consuming 1450 calories. How long did he play tennis? <BR>\n" );
document.write( "I've been trying to come up with something like 25x + 35y = 1450 but I can't go from there. <BR>\n" );
document.write( "I'd be grateful if you could quickly give me some idea how to do the above. <BR>\n" );
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document.write( "25x + 35y = 1450 is the right approach, but I'll use t and c<BR>\n" );
document.write( "25t + 35c = 1450 (same thing)<BR>\n" );
document.write( "t + c = 50 (the missing piece)<BR>\n" );
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document.write( "5t + 7c = 290 (reduced, smaller numbers)<BR>\n" );
document.write( "Substitute t = 50-c<BR>\n" );
document.write( "5*(50-c) + 7c = 290<BR>\n" );
document.write( "250 - 5c + 7c = 290<BR>\n" );
document.write( "2c = 40<BR>\n" );
document.write( "c = 20<BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "Then t = 30\r<BR>\n" );
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document.write( " </SPAN>\n" );
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