document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=490758>Question 490758</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I am not sure if I chose the right topic to type this under: I have to use the substitution method to solve systems of equations. the problem I have is:<BR>\n" );
document.write( "2x + 2y = 41<BR>\n" );
document.write( "x + 2y = 0 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #334289 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=334289\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Start off by solving for x in the second equation to go from <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%2B2y=0 ALIGN=MIDDLE  ALT=\"x%2B2y=0\"   DISABLED_style= \"max-width:90%; height:auto;\" > to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=-2y ALIGN=MIDDLE  ALT=\"x=-2y\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Now go back to the first equation and replace each copy of x with -2y (this is legal since x = -2y)\r<BR>\n" );
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document.write( "So the first equation goes from <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2x%2B2y=41 ALIGN=MIDDLE  ALT=\"2x%2B2y=41\"   DISABLED_style= \"max-width:90%; height:auto;\" > and becomes <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%28-2y%29%2B2y=41 ALIGN=MIDDLE  ALT=\"2%28-2y%29%2B2y=41\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "This is why this method is known as the substitution method. In that last step, I <u>substituted</u> x for -2y. Doing this got rid of one variable so you can solve for the other.\r<BR>\n" );
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document.write( "So at this point, you have a linear equation with one variable (y). Solve this equation to find the value of y. Once you have y, use that to find x. You do this by plugging it into <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=-2y ALIGN=MIDDLE  ALT=\"x=-2y\"   DISABLED_style= \"max-width:90%; height:auto;\" > and evaluating. </SPAN>\n" );
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