document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=166102>Question 166102</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A collection of triangles and pentagons contains 40 shapes having a total of 138 sides. How many pentagons are there? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #122382 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=122382\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A collection of triangles and pentagons contains 40 shapes having a total of 138 sides. How many pentagons are there?<BR>\n" );
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document.write( "# of shapes equation: p + t = 40<BR>\n" );
document.write( "# of sides equation: 5p +3t = 138<BR>\n" );
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document.write( "Multiply thru 1st by 3 to get:<BR>\n" );
document.write( "3p + 3t = 120<BR>\n" );
document.write( "5p + 3t = 138<BR>\n" );
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document.write( "Subtract 1st from 2nd to get:<BR>\n" );
document.write( "2p = 18<BR>\n" );
document.write( "p = 9 (# of pentagons)<BR>\n" );
document.write( "Since p + t = 40, t = 31 (# of triangles)<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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