document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=63560>Question 63560</A>: <I><SPAN STYLE=\"word-break: break-all;\"> .the area of a square bookcase is 21 more than the perimeter. find the length of a side </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #44268 by </B><A HREF=/tutors/aboutme.mpl?userid=joyofmath><B>joyofmath(189)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=joyofmath><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=44268\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <b>.the area of a square bookcase is 21 more than the perimeter. find the length of a side</b>\r<BR>\n" );
document.write( "\n" );
document.write( "Let L = the side of the bookcase.<BR>\n" );
document.write( "Let P = the perimeter of the bookcase.<BR>\n" );
document.write( "Let A = the area of the bookcase.\r<BR>\n" );
document.write( "\n" );
document.write( "Then, we know that:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=P%2B21 ALIGN=MIDDLE  ALT=\"A=P%2B21\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=L%5E2 ALIGN=MIDDLE  ALT=\"A=L%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=P=4L ALIGN=MIDDLE  ALT=\"P=4L\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "So, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=L%5E2=P%2B21 ALIGN=MIDDLE  ALT=\"A=L%5E2=P%2B21\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "But, P=4L so <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=L%5E2=4L%2B21 ALIGN=MIDDLE  ALT=\"A=L%5E2=4L%2B21\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "So, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L%5E2+=+4L%2B21 ALIGN=MIDDLE  ALT=\"L%5E2+=+4L%2B21\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "Or, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L%5E2-4L-21=0 ALIGN=MIDDLE  ALT=\"L%5E2-4L-21=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "This factors to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28L%2B3%29%28L-7%29=0 ALIGN=MIDDLE  ALT=\"%28L%2B3%29%28L-7%29=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "So, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L=-3 ALIGN=MIDDLE  ALT=\"L=-3\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L=7 ALIGN=MIDDLE  ALT=\"L=7\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
document.write( "\n" );
document.write( "The length can't be negative so <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L=7 ALIGN=MIDDLE  ALT=\"L=7\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
document.write( "\n" );
document.write( "Let's verify the answer.\r<BR>\n" );
document.write( "\n" );
document.write( "If <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L=7 ALIGN=MIDDLE  ALT=\"L=7\"   DISABLED_style= \"max-width:90%; height:auto;\" > then <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=P=4%2A7=28 ALIGN=MIDDLE  ALT=\"P=4%2A7=28\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=L%5E2=7%5E2=49 ALIGN=MIDDLE  ALT=\"A=L%5E2=7%5E2=49\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "So, A is indeed 21 more than P. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );