document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=884751>Question 884751</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A rectangular sheet of metal is 30 in by 40 in. An open rectangular box is made by cutting squares of equal areas from the four corners and folding up the ends. if the area of the base of the box is 336 inches square, find the total area of the discarded squares </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #534657 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=534657\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A rectangular sheet of metal is 30 in by 40 in.<BR>\n" );
document.write( " An open rectangular box is made by cutting squares of equal areas from the four corners and folding up the ends.<BR>\n" );
document.write( " if the area of the base of the box is 336 inches square, find the total area of the discarded squares.\<BR>\n" );
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document.write( "Let x = length of the side of one of the squares, also the height of the box<BR>\n" );
document.write( "then<BR>\n" );
document.write( "x^2 = area of one of the squares<BR>\n" );
document.write( "and<BR>\n" );
document.write( "4x^2 = the total area of the 4 squares<BR>\n" );
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document.write( "If the area of the base is 336 then the volume of the box = 336x cu in<BR>\n" );
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document.write( "the dimensions of the box:<BR>\n" );
document.write( "(30-2x) by (40-2x) by x<BR>\n" );
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document.write( "The volume equation<BR>\n" );
document.write( "(30-2x)(40-2x)*x = 336x<BR>\n" );
document.write( "Divide both sides by x<BR>\n" );
document.write( "(30-2x)(40-2x) = 336<BR>\n" );
document.write( "FOIL<BR>\n" );
document.write( "1200 - 60x - 80x + 4x^2 = 336<BR>\n" );
document.write( "Form a quadratic equation<BR>\n" );
document.write( "4x^2 - 140x + 1200 - 336 = 0<BR>\n" );
document.write( "4x^2 - 140x + 864 = 0<BR>\n" );
document.write( "simplify, divide by 4<BR>\n" );
document.write( "x^2 - 35x + 216 = 0<BR>\n" );
document.write( "you can use the quadratic formula, but this will factor<BR>\n" );
document.write( "x = 27<BR>\n" );
document.write( "x = 8; this is only solution that will make sense<BR>\n" );
document.write( "then<BR>\n" );
document.write( "4(8^2) = 512 sq/in is the area of the removed squares<BR>\n" );
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document.write( "Check this, find the area of the base by subtracting 2x (16), from 40 and 30<BR>\n" );
document.write( "14 * 24 = 336<BR>\n" );
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