document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1163956>Question 1163956</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the equation of the linear function that contains the points (1, 4) and (3, −2). </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #788235 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13215)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=788235\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "A great many students find it easy to use the formula for finding the slope between two points incorrectly, ending up with the wrong slope.  That of course makes the rest of their work useless.<br><BR>\n" );
document.write( "I strongly recommend that students have at least a mental picture -- if not a sketch with pencil and paper -- to use for finding the slope.<br><BR>\n" );
document.write( "From (1,4) to (3,-2), you move 2 to the right (from 1 to 3) and 6 down (from 4 to -2).  The \"run\" (change in x) is 2; the \"rise\" (change in y) is -6.  The slope is rise over run = -6/2 = -3.<br><BR>\n" );
document.write( "So the equation is of the form<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+-3x%2Bb ALIGN=MIDDLE  ALT=\"y+=+-3x%2Bb\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "To find the constant b, substitute the x and y values of either of the given points.<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4+=+-3%281%29%2Bb ALIGN=MIDDLE  ALT=\"4+=+-3%281%29%2Bb\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4+=+-3%2Bb ALIGN=MIDDLE  ALT=\"4+=+-3%2Bb\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7+=+b ALIGN=MIDDLE  ALT=\"7+=+b\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "The equation of the line containing the two points is<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+-3x%2B7 ALIGN=MIDDLE  ALT=\"y+=+-3x%2B7\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );