document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1187458>Question 1187458</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In the diagram, Line BE=80 cm, and Line AC=Line DC. Find the length of Line BC, in cm.\r<BR>\n" );
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document.write( "Diagram:<BR>\n" );
document.write( "https://ibb.co/dL2T5DW </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #818463 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=818463\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> In the diagram, Line BE=80 cm, and Line AC=Line DC. Find the length of Line BC, in cm.<BR>\n" );
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document.write( "Label BC = x and AC = DC = z to save some typing.<BR>\n" );
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document.write( "z^2 - 32^2 = x^2<BR>\n" );
document.write( "z^2 - 40^2 = (80-x)^2<BR>\n" );
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document.write( "z^2 - 1024 = x^2<BR>\n" );
document.write( "z^2 - 1600 = 6400 - 160x + x^2<BR>\n" );
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document.write( "Sub for z^2 in the 2nd equation<BR>\n" );
document.write( "x^2+1024 - 1600 = x^2 - 160x + 6400<BR>\n" );
document.write( "-576 = -160x + 6400<BR>\n" );
document.write( "160x = 6976<BR>\n" );
document.write( "x = 43.6 cm<BR>\n" );
document.write( "BC = 43.6 cm<BR>\n" );
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