document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=124368>Question 124368</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Perimeter of a rectangle.  The width of a rectangular playground is 2x-5 feet and the length is 3x+9 feet.  Write a polynomial P(x) that represents the perimeter and then evaluate this perimeter polynomial if x is 4 feet. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #91142 by </B><A HREF=/tutors/aboutme.mpl?userid=bucky><B>bucky(2189)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=bucky><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=91142\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let W represent the width of the rectangle and L represent the length.<BR>\n" );
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document.write( "The perimeter (P) is defined as the sum of the lengths of the sides of a polygon. In this case<BR>\n" );
document.write( "the perimeter of this rectangle is found by adding the 4 sides. In equation form this is:<BR>\n" );
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document.write( "P = W + L + W + L<BR>\n" );
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document.write( "And by combining like terms on the right side this reduces to:<BR>\n" );
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document.write( "P = 2W + 2L<BR>\n" );
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document.write( "The problem tells you that the width W is equal to 2x - 5 feet. Substitute this for W in the<BR>\n" );
document.write( "perimeter equation and it becomes:<BR>\n" );
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document.write( "P = 2(2x - 5) + 2L<BR>\n" );
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document.write( "The problem also tells you that the length L is equal to 3x + 9 feet. Substitute this for L in<BR>\n" );
document.write( "the perimeter equation and it then becomes:<BR>\n" );
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document.write( "P = 2(2x - 5) + 2(3x + 9)<BR>\n" );
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document.write( "Do the two distributed multiplications on the right side to get:<BR>\n" );
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document.write( "P = 4x - 10 + 6x + 18<BR>\n" );
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document.write( "Combine the like terms on the right side ... the 4x and 6x combine to give 10x and the<BR>\n" );
document.write( "-10 and the +18 combine to +8. Substitute these results and the perimeter equation <BR>\n" );
document.write( "reduces to the polynomial form:<BR>\n" );
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document.write( "P = 10x + 8 in units of feet<BR>\n" );
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document.write( "That's the equation you needed to find. Then the problem asks if x is 4 feet, what is the<BR>\n" );
document.write( "perimeter. Substitute 4 for x and you get:<BR>\n" );
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document.write( "P = 10(4) + 8 = 40 + 8 = 48 feet<BR>\n" );
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document.write( "check ... if x is 4 feet then the width (given by 2x - 5) is 3 feet and the length <BR>\n" );
document.write( "(given by 3x + 9 is 21 feet. Therefore, the perimeter is 3 + 21 + 3 + 21 = 48 feet. That checks.<BR>\n" );
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document.write( "Hope this helps you to understand the problem.<BR>\n" );
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document.write( " </SPAN>\n" );
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