document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=638348>Question 638348</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How do you write a linear equation from x and y coordinates </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #402146 by </B><A HREF=/tutors/aboutme.mpl?userid=MathLover1><B>MathLover1(20849)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathLover1><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=MathLover1><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=402146\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "1.<BR>\n" );
document.write( "Find the slope of the line by dividing the change in y-coordinates by the change in x-coordinates: \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=slope+=+%28y2+-+y1%29%2F%28x2+-+x1%29 ALIGN=MIDDLE  ALT=\"slope+=+%28y2+-+y1%29%2F%28x2+-+x1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >. \r<BR>\n" );
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document.write( "For example, given the coordinates (2, 0) and (-1, 3), the <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=slope+=+%283+-+0%29%2F%28-1+-+2%29+=+-1 ALIGN=MIDDLE  ALT=\"slope+=+%283+-+0%29%2F%28-1+-+2%29+=+-1\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "If both of the x-coordinates equal some value <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=k ALIGN=MIDDLE  ALT=\"k\"   DISABLED_style= \"max-width:90%; height:auto;\" >, the slope and y-intercept are undefined, and the equation for the line will be <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+k ALIGN=MIDDLE  ALT=\"x+=+k\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "2.\r<BR>\n" );
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document.write( "Calculate the y-intercept by multiplying the slope times one of the x-coordinates and subtracting the product from the y-coordinate of the same point: \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y-intercept+=+y1+-+slope%2Ax1 ALIGN=MIDDLE  ALT=\"y-intercept+=+y1+-+slope%2Ax1\"   DISABLED_style= \"max-width:90%; height:auto;\" >, where <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x1 ALIGN=MIDDLE  ALT=\"x1\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y1 ALIGN=MIDDLE  ALT=\"y1\"   DISABLED_style= \"max-width:90%; height:auto;\" > are coordinates of one of the given points. \r<BR>\n" );
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document.write( "For example, knowing that the <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=slope+=+-1 ALIGN=MIDDLE  ALT=\"slope+=+-1\"   DISABLED_style= \"max-width:90%; height:auto;\" >, use the point (2, 0): <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y-intercept+=+0+-+%28-1%29%2A2+=+2 ALIGN=MIDDLE  ALT=\"y-intercept+=+0+-+%28-1%29%2A2+=+2\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "3.\r<BR>\n" );
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document.write( "Write the equation for the line in the <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=slope-intercept ALIGN=MIDDLE  ALT=\"slope-intercept\"   DISABLED_style= \"max-width:90%; height:auto;\" > format: \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+slope%2Ax+%2B+y-intercept ALIGN=MIDDLE  ALT=\"y+=+slope%2Ax+%2B+y-intercept\"   DISABLED_style= \"max-width:90%; height:auto;\" >. \r<BR>\n" );
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document.write( "In the given example, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+-x+%2B+2 ALIGN=MIDDLE  ALT=\"y+=+-x+%2B+2\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "4.\r<BR>\n" );
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document.write( "Verify the equation by plugging in the <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x ALIGN=MIDDLE  ALT=\"x\"   DISABLED_style= \"max-width:90%; height:auto;\" >- and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y-coordinates ALIGN=MIDDLE  ALT=\"y-coordinates\"   DISABLED_style= \"max-width:90%; height:auto;\" > of the given points. If the equation remains balanced after simplifying, your equation is good. \r<BR>\n" );
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document.write( "For example, given the equation <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+-x+%2B+2 ALIGN=MIDDLE  ALT=\"y+=+-x+%2B+2\"   DISABLED_style= \"max-width:90%; height:auto;\" >, plug in the first point (2,0): \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0+=+-2+%2B+2 ALIGN=MIDDLE  ALT=\"0+=+-2+%2B+2\"   DISABLED_style= \"max-width:90%; height:auto;\" >. That's true, so everything checks out so far. \r<BR>\n" );
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document.write( "Try again with (-1, 3): <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3+=+1+%2B+2 ALIGN=MIDDLE  ALT=\"3+=+1+%2B+2\"   DISABLED_style= \"max-width:90%; height:auto;\" >. That's true too, so the equation is good.\r<BR>\n" );
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