document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1004519>Question 1004519</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Two students used a graphing method to solve the system of equations.\r<BR>\n" );
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document.write( "-4x+3y=5<BR>\n" );
document.write( "2x+3y=-16\r<BR>\n" );
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document.write( "They used substitution to verify their solutions. Which student is correct? Explain the error.\r<BR>\n" );
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document.write( "STUDENT A:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-4%28-3.5%29%2B3%28-3%29=5 ALIGN=MIDDLE  ALT=\"-4%28-3.5%29%2B3%28-3%29=5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%28-3.5%29%2B3%28-3%29=-16 ALIGN=MIDDLE  ALT=\"2%28-3.5%29%2B3%28-3%29=-16\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "STUDENT B<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%284%29%2B3%287%29=-16 ALIGN=MIDDLE  ALT=\"2%284%29%2B3%287%29=-16\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Thank you to anyone who can help! I sort of have an idea of how to solve this, but I'm not totally sure if it's correct. <BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #620980 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=620980\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The only solution is (x,y) = (-3.5, -3). Student A has the right idea.\r<BR>\n" );
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document.write( "-4x+3y = 5<BR>\n" );
document.write( "-4(-3.5)+3(-3)=5<BR>\n" );
document.write( "14-9 = 5<BR>\n" );
document.write( "5 = 5 ... true\r<BR>\n" );
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document.write( "2x+3y=-16 <BR>\n" );
document.write( "2(-3.5)+3(-3) = -16<BR>\n" );
document.write( "-7-9 = -16<BR>\n" );
document.write( "-16 = -16 ... true\r<BR>\n" );
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document.write( "Both equations are true when (x,y) = (-3.5, -3), so the solution is confirmed.\r<BR>\n" );
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document.write( "Student B used the wrong values for x and y\r<BR>\n" );
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document.write( "-4x+3y = 5<BR>\n" );
document.write( "-4(4)+3(7) = 5<BR>\n" );
document.write( "-16+21 = 5<BR>\n" );
document.write( "5 = 5 ... true\r<BR>\n" );
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document.write( "2x+3y=-16 <BR>\n" );
document.write( "2(4)+3(7)=-16 <BR>\n" );
document.write( "8+21=-16 <BR>\n" );
document.write( "29 = -16 ... false\r<BR>\n" );
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document.write( "(x,y) = (4,7) makes the first equation true but the second equation false. Since it doesn't make both equations true, this means that (x,y) = (4,7) is NOT a solution.\r<BR>\n" );
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