document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1070318>Question 1070318</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 3x+5y-z=1<BR>\n" );
document.write( "4x+7y+z=2 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #685427 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39617)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=685427\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%283x%2B5y=1%2Bz%2C4x%2B7y=2-z%29 ALIGN=MIDDLE  ALT=\"system%283x%2B5y=1%2Bz%2C4x%2B7y=2-z%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Make z as some constant:  k=z.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%283x%2B5y=1%2Bk%2C4x%2B7y=2-k%29 ALIGN=MIDDLE  ALT=\"system%283x%2B5y=1%2Bk%2C4x%2B7y=2-k%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Prepare to use Elimination.<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%2812x%2B60y=12%2B12k%2C12x%2B21y=6-6k%29 ALIGN=MIDDLE  ALT=\"system%2812x%2B60y=12%2B12k%2C12x%2B21y=6-6k%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Subtract second from first.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=13y=2%2B6k ALIGN=MIDDLE  ALT=\"13y=2%2B6k\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28y=%282%2B6k%29%2F13%29 ALIGN=MIDDLE  ALT=\"highlight%28y=%282%2B6k%29%2F13%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%2821x%2B35y=7%2B7k%2C20x%2B35y=10-5k%29 ALIGN=MIDDLE  ALT=\"system%2821x%2B35y=7%2B7k%2C20x%2B35y=10-5k%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "subtract second from first.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28x=-3%2B12k%29 ALIGN=MIDDLE  ALT=\"highlight%28x=-3%2B12k%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "k and z were made the same, so you can pick any real value for k (or z) and find the corresponding x and y values.  Infinitely many solutions to the three-variable, two-equation system. </SPAN>\n" );
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