document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=74951>Question 74951</A>: <I><SPAN STYLE=\"word-break: break-all;\"> on a farm there are 65 animals, all cows and ducks.  The 65 animals have a total of 224 legs.  How many cows and ducks are there? Justify your answer. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #53927 by </B><A HREF=/tutors/aboutme.mpl?userid=ptaylor><B>ptaylor(2198)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ptaylor><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=ptaylor><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=53927\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let x=number of ducks------they have 2 legs\r<BR>\n" );
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document.write( "And y=number of cows------------------they have 4 legs\r<BR>\n" );
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document.write( "Now we are told that:\r<BR>\n" );
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document.write( "x+y=65---------------------------eq 1 (subtract y from both sides)<BR>\n" );
document.write( "x=65-y\r<BR>\n" );
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document.write( "Now we are also told that:\r<BR>\n" );
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document.write( "2x+4y=224------------------------------eq 2\r<BR>\n" );
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document.write( "We will solve by substitution.  Substitute x=65-y from eq 1 into eq 2\r<BR>\n" );
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document.write( "2(65-y)+4y=224  get rid of parens<BR>\n" );
document.write( "130-2y+4y=224  subtract 130 from both sides\r<BR>\n" );
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document.write( "130-130-2y+4y=224-130  collect like terms\r<BR>\n" );
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document.write( "2y=94  divide both sides by 2<BR>\n" );
document.write( "y=47----------------------------------------# of cows\r<BR>\n" );
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document.write( "Substitute y=47 into eq 1:<BR>\n" );
document.write( "x+47=65  subtract 47 from both sides<BR>\n" );
document.write( "x=65-47<BR>\n" );
document.write( "x=18------------------------------------------# of ducks\r<BR>\n" );
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document.write( "CK\r<BR>\n" );
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document.write( "2*18+4*47=224<BR>\n" );
document.write( "36+188=224<BR>\n" );
document.write( "224=224\r<BR>\n" );
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document.write( "Hope this helps----ptaylor </SPAN>\n" );
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