document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=234599>Question 234599</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the value of x so that angleABC is a right angle, given the following coordinates : A(x,7) B(-3,x) C(-1,0) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #173003 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=173003\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find the value of x so that angleABC is a right angle, given the following coordinates : A(x,7) B(-3,x) C(-1,0)<BR>\n" );
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document.write( "AB is perpendicular to BC.<BR>\n" );
document.write( "slope of AB = (7-x)/(x+3)<BR>\n" );
document.write( "slope of BC = x/(-3+1) = -x/2<BR>\n" );
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document.write( "the slopes are negative inverses<BR>\n" );
document.write( "(x+3)/(7-x) = x/2<BR>\n" );
document.write( "2(x+3) = x(7-x)<BR>\n" );
document.write( "-x^2 + 7x = 2x + 6<BR>\n" );
document.write( "x^2 - 5x + 6 = 0<BR>\n" );
document.write( "x = 2<BR>\n" );
document.write( "x = 3<BR>\n" );
document.write( "  </SPAN>\n" );
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