document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=400208>Question 400208</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How do I find the equation of the line joining the following pairs of points:\r<BR>\n" );
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document.write( "1. (1,8) and (-1,-20)\r<BR>\n" );
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document.write( "2. (2,-1) and (3,5) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #285147 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=285147\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> How do I find the equation of the line joining the following pairs of points:<BR>\n" );
document.write( "1. (1,8) and (-1,-20)<BR>\n" );
document.write( "2. (2,-1) and (3,5)\r<BR>\n" );
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document.write( "..\r<BR>\n" );
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document.write( "These equations can take one of two forms: slope-intercept or point-slope. I will do the former, y=mx+b, m being the slope and b the y-intercept. The problem is to find the slope,m, and the  y-intercept,b.\r<BR>\n" );
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document.write( "1. slope=change in y/change in x or rise/run.<BR>\n" );
document.write( "        =8-(-20)/1-(-1)=28/2=14<BR>\n" );
document.write( "   y=14x+b<BR>\n" );
document.write( "   using first ordered pair(1,8) (using either pair is ok)<BR>\n" );
document.write( "   8=14(1)+b<BR>\n" );
document.write( "   b=8-14=-6<BR>\n" );
document.write( "   equation: y=14x-6<BR>\n" );
document.write( "..\r<BR>\n" );
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document.write( "2. slope=change in y/change in x or rise/run.<BR>\n" );
document.write( "        =(-1-5)/(2-3)=-6/-1=6<BR>\n" );
document.write( "   y=6x+b<BR>\n" );
document.write( "   using first ordered pair(2,-1) (using either pair is ok)<BR>\n" );
document.write( "   -1=6(2)+b<BR>\n" );
document.write( "   b=-12-1=-13<BR>\n" );
document.write( "   equation: y=6x-13\r<BR>\n" );
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document.write( "See these two equations on the graph below:\r<BR>\n" );
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document.write( "..\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+300%2C+200%2C+-6%2C+5%2C+-20%2C+10%2C+14x-6%2C6x-13%29+ ALIGN=MIDDLE  ALT=\"+graph%28+300%2C+200%2C+-6%2C+5%2C+-20%2C+10%2C+14x-6%2C6x-13%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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