document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=136435>Question 136435</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find an equation of the line containing the given pair of points.<BR>\n" );
document.write( "(-3, -2) and (-7, -1)<BR>\n" );
document.write( "The equation of line y is?<BR>\n" );
document.write( "Help please. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #99964 by </B><A HREF=/tutors/aboutme.mpl?userid=algebrapro18><B>algebrapro18(249)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=algebrapro18><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=99964\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> First you need to fine the slope of this line.  You do this using the formula for slope which is:<br>\r<BR>\n" );
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document.write( "m = (y2-y1)/(x2-x1)where<BR>\n" );
document.write( "x1 = -3<BR>\n" );
document.write( "y1 = -2<BR>\n" );
document.write( "x2 = -7<BR>\n" );
document.write( "y2 = -1<br>\r<BR>\n" );
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document.write( "now plugging in you get<br>\r<BR>\n" );
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document.write( "m = (-1-(-2))/(-7-(-3))<BR>\n" );
document.write( "m = (-1+2)/(-7+3)<BR>\n" );
document.write( "m = 1/-4<BR>\n" );
document.write( "m = -1/4<br>\r<BR>\n" );
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document.write( "now that we know the slope we can find the equation of the line in two ways.<br>\r<BR>\n" );
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document.write( "Method 1: solving y=mx+b for b<br>\r<BR>\n" );
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document.write( "Now that we have numbers for y,m, and x we can plug those into the slope-intercept formula and solve for b.<br>\r<BR>\n" );
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document.write( "y = mx + b<BR>\n" );
document.write( "-1 = -1/4(-7) + b<BR>\n" );
document.write( "-1 = 7/4 + b<BR>\n" );
document.write( "-11/4 = b<br>\r<BR>\n" );
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document.write( "y = -1/4x - 11/4<br>\r<BR>\n" );
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document.write( "Method 2: use the point slope formula and solve for y<br>\r<BR>\n" );
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document.write( "There is another formula you may not have used yet, its call the point slope formula.  It looks like this:<br>\r<BR>\n" );
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document.write( "y-y1=m(x-x1)where<BR>\n" );
document.write( "x1 = -3<BR>\n" );
document.write( "y1 = -2<br>\r<BR>\n" );
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document.write( "now plugging in you get<br>\r<BR>\n" );
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document.write( "y-(-2)=-1/4(x-(-3))<BR>\n" );
document.write( "y+2 = -1/4(x+3)<BR>\n" );
document.write( "y = -1/4x - 3/4 -2<BR>\n" );
document.write( "y = -1/4x - 11/4<br>\r<BR>\n" );
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document.write( "Either method you use will give you the same line so really its personal preference(or what ever way your teacher specifies). </SPAN>\n" );
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