document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=883353>Question 883353</A>: <I><SPAN STYLE=\"word-break: break-all;\"> When we use square tiles of unknown length to cover a floor, we require 128 tiles. If the side of the tile is decreased by 2 cm, we require 200 tiles. Find the side of the larger tile.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #533555 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=533555\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> When we use square tiles of unknown length to cover a floor, we require 128 tiles.<BR>\n" );
document.write( " If the side of the tile is decreased by 2 cm, we require 200 tiles.<BR>\n" );
document.write( " Find the side of the larger tile.<BR>\n" );
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document.write( "let x = side of the larger tile<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(x-2) = side of the smaller<BR>\n" );
document.write( "then<BR>\n" );
document.write( "128x^2 = size of the floor<BR>\n" );
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document.write( "The equation<BR>\n" );
document.write( "200(x-2)^2 = 128x^2<BR>\n" );
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document.write( "Simplify, divide by 8<BR>\n" );
document.write( "25(x-2)^2 = 16x^2<BR>\n" );
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document.write( "FOIL (x-2)(x-2)<BR>\n" );
document.write( "25(x^2 - 4x + 4) = 16x^2<BR>\n" );
document.write( "25x^2 - 100x + 100 = 16x^2<BR>\n" );
document.write( "25x^2 - 16x^2 - 100x + 100 = 0<BR>\n" );
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document.write( "A quadratic equation<BR>\n" );
document.write( "9x^2 - 100x + 100 = 0<BR>\n" );
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document.write( "you can use the quadratic formula here, but this will factor to:<BR>\n" );
document.write( "(9x-10)(x-10) = 0<BR>\n" );
document.write( "x = 10 cm is the reasonable answer<BR>\n" );
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document.write( "See if that works<BR>\n" );
document.write( "Find the area of the floor: 128(10^2) = 12800 sq/cm<BR>\n" );
document.write( "Find the area of the smaller tile<BR>\n" );
document.write( "8*8 = 64 sq/cm<BR>\n" );
document.write( "Find how many of these tiles are required to cover 2800sq/cm<BR>\n" );
document.write( "12800/64 = 200 tiles<BR>\n" );
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