document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=3630>Question 3630</A>: <I><SPAN STYLE=\"word-break: break-all;\"> what is  the equation form  passing through lines (1,3)and (-1,2) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #1612 by </B><A HREF=/tutors/aboutme.mpl?userid=AnlytcPhil><B>AnlytcPhil(1810)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=AnlytcPhil><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=AnlytcPhil><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=1612\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font face = \"courier new\" size = 2><BR>\n" );
document.write( ">>...What is the equation form passing through lines (1,3) and (-1,2)...<<<BR>\n" );
document.write( "`<font size = 3 color = \"blue\"><b><BR>\n" );
document.write( "The equation of the line passing through two points (x<sub>1</sub>,y<sub>1</sub>) and (x<sub>2</sub>,y<sub>2</sub>) <BR>\n" );
document.write( "is: <BR>\n" );
document.write( "`<BR>\n" );
document.write( "` ` `y - y<sub>1</sub> = m(x - x<sub>1</sub>)<BR>\n" );
document.write( "`<BR>\n" );
document.write( "where<BR>\n" );
document.write( "``<BR>\n" );
document.write( "` ` ` ` ` y<sub>2</sub> - y<sub>1</sub><BR>\n" );
document.write( "` ` `m = —————————<BR>\n" );
document.write( "` ` ` ` ` x<sub>2</sub> - x<sub>1</sub><BR>\n" );
document.write( "`<BR>\n" );
document.write( "In this case (x<sub>1</sub>,y<sub>1</sub>) = (1,3) and (x<sub>2</sub>,y<sub>2</sub>) = (-1,2)<BR>\n" );
document.write( "`<BR>\n" );
document.write( "First substitute in the formula for m:<BR>\n" );
document.write( "`<BR>\n" );
document.write( "` ` ` ` ` y<sub>2</sub> - y<sub>1</sub><BR>\n" );
document.write( "` ` `m = —————————<BR>\n" );
document.write( "` ` ` ` ` x<sub>2</sub> - x<sub>1</sub><BR>\n" );
document.write( "`<BR>\n" );
document.write( "` ` ` ` ` (2) - (3)<BR>\n" );
document.write( "` ` `m = ———————————<BR>\n" );
document.write( "` ` ` ` `(-1) - (1)<BR>\n" );
document.write( "`<BR>\n" );
document.write( "` ` ` ` `-1` ` `1<BR>\n" );
document.write( "` ` `m = ——— = ———<BR>\n" );
document.write( "` ` ` ` `-2` ` `2<BR>\n" );
document.write( "`<BR>\n" );
document.write( "Now substitute 1/2 for m, 1 for x<sub>1</sub>, 3 for y<sub>1</sub>, -1 for x<sub>2</sub> and 3 for y<sub>2</sub><BR>\n" );
document.write( "in the formula<BR>\n" );
document.write( "`<BR>\n" );
document.write( "` ` `y - y<sub>1</sub> = m(x - x<sub>1</sub>)<BR>\n" );
document.write( "`<BR>\n" );
document.write( "` ` ` y - 3 = (1/2)(x - 1)<BR>\n" );
document.write( "`<BR>\n" );
document.write( "Now clear of fractions by multiplying both side by 2<BR>\n" );
document.write( "`<BR>\n" );
document.write( "` `2[y - 3] = 2[(1/2)(x - 1]<BR>\n" );
document.write( "`<BR>\n" );
document.write( "` `2[y - 3] = <s>2</s>[1/<s>2</s>)(x - 1]<BR>\n" );
document.write( "`<BR>\n" );
document.write( "` ` `2y - 6 = x - 1<BR>\n" );
document.write( "`<BR>\n" );
document.write( "The standard form is to have the x-term first, then the y-term, <BR>\n" );
document.write( "then an equal sign and then a number:<BR>\n" );
document.write( "`<BR>\n" );
document.write( "` ` `-x + 2y = 6 - 1<BR>\n" );
document.write( "`<BR>\n" );
document.write( "` ` `-x + 2y = 5<BR>\n" );
document.write( "`<BR>\n" );
document.write( "The standard form is considered  best when the x-term is positive,<BR>\n" );
document.write( "so multiply through by -1<BR>\n" );
document.write( "`<BR>\n" );
document.write( "` ` ` `x - 2y = -5<BR>\n" );
document.write( "`<BR>\n" );
document.write( "Edwin <font face = \"wingdings\" size = 7 color = \"red\">J</font><BR>\n" );
document.write( "    </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );