document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=4796>Question 4796</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Solve the problem:\r<BR>\n" );
document.write( "\n" );
document.write( "The printed matter on a 12 by 18 centimeter page of a book must cover 40 square centimeters.  If all margins are to be the same width, how wide should the margins be? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #2330 by </B><A HREF=/tutors/aboutme.mpl?userid=Abbey><B>Abbey(339)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Abbey><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=2330\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let L = Length of printed matter<BR>\n" );
document.write( "Let W = Width of printed matter<BR>\n" );
document.write( "let M = Margin<BR>\n" );
document.write( "Area of printed matter = 40 = L*W Length of page = 18cm = 2M+L<BR>\n" );
document.write( "Width of page =  12cm = 2M+W\r<BR>\n" );
document.write( "\n" );
document.write( "Using the elimination method:<BR>\n" );
document.write( "18=2M+L<BR>\n" );
document.write( "12=2M+W\r<BR>\n" );
document.write( "\n" );
document.write( "Subtract the 2nd equation from the first to get<BR>\n" );
document.write( "6=L-W<BR>\n" );
document.write( "add w to both sides:<BR>\n" );
document.write( "6+W=L\r<BR>\n" );
document.write( "\n" );
document.write( "Use the substitution method on the area equation to get:<BR>\n" );
document.write( "40=(6+W)*W\r<BR>\n" );
document.write( "\n" );
document.write( "Clear the parentheses:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=40=6W%2BW%5E2 ALIGN=MIDDLE  ALT=\"40=6W%2BW%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Subtract 40 from both sides to set equal to zero and solve for x:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0=W%5E2%2B6w-40 ALIGN=MIDDLE  ALT=\"0=W%5E2%2B6w-40\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Factor:<BR>\n" );
document.write( "(w+10)(w-4)<BR>\n" );
document.write( "w=-10, w=4\r<BR>\n" );
document.write( "\n" );
document.write( "We can eliminate the negative because this is a distance we are discussing, so the width of the printed matter is 4cm<BR>\n" );
document.write( "the length of the printed matter is 10 cm\r<BR>\n" );
document.write( "\n" );
document.write( "Going back to the system of equations, we know the page length is <BR>\n" );
document.write( "18=2M+L<BR>\n" );
document.write( "18=2M+10<BR>\n" );
document.write( "8=2M<BR>\n" );
document.write( "4=M\r<BR>\n" );
document.write( "\n" );
document.write( "The margin is 4 cm.  <BR>\n" );
document.write( "Check by adding the margins to the width and length. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );